diff --git a/.gitattributes b/.gitattributes
index 5380433..82ad3c9 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,4 +1,4 @@
-.gitattributes export-ignore
+.github export-ignore
 .gitignore export-ignore
 .travis.yml export-ignore
 composer.json export-ignore
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
new file mode 100644
index 0000000..0c2653d
--- /dev/null
+++ b/.github/workflows/tests.yml
@@ -0,0 +1,27 @@
+name: Tests
+
+on: [push, pull_request]
+
+jobs:
+    tests:
+        runs-on: ubuntu-latest
+        strategy:
+            fail-fast: false
+            matrix:
+                php: [8.0, 8.1, 8.2, 8.3, 8.4, 8.5]
+
+        name: PHP ${{ matrix.php }} tests
+        steps:
+            - uses: actions/checkout@v4
+            - uses: shivammathur/setup-php@v2
+              with:
+                    php-version: ${{ matrix.php }}
+                    coverage: none
+
+            - run: composer install --no-progress --prefer-dist
+            - run: vendor/bin/tester tests -s
+            - if: failure()
+              uses: actions/upload-artifact@v4
+              with:
+                  name: output
+                  path: tests/**/output
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 0c4f559..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,24 +0,0 @@
-language: php
-
-php:
-    - 5.4
-    - 5.5
-    - 5.6
-    - hhvm
-
-matrix:
-    allow_failures:
-        - php: hhvm
-
-before_script:
-    # Update composer
-    - composer self-update
-
-    # Install Nette Tester
-    - composer install --no-interaction --dev --prefer-source
-
-script: vendor/bin/tester -p php -s tests
-
-after_failure:
-    # Print *.actual content
-    - for i in $(find tests -name \*.actual); do echo "--- $i"; cat $i; echo; echo; done
diff --git a/composer.json b/composer.json
index 1194de8..c01c964 100644
--- a/composer.json
+++ b/composer.json
@@ -1,7 +1,7 @@
 {
 	"name": "milo/github-api",
 	"type": "library",
-	"description": "Github API easy access",
+	"description": "GitHub API easy access",
 	"license": ["MIT"],
 	"authors": [
 		{
@@ -11,10 +11,10 @@
 		}
 	],
 	"require": {
-		"php": ">=5.4.0"
+		"php": "8.0 - 8.5"
 	},
 	"require-dev": {
-		"nette/tester": "~1.3.0"
+		"nette/tester": "^2.4"
 	},
 	"suggest": {
 		"ext-curl": "Allows you to use Http\\CurlClient"
diff --git a/readme.md b/readme.md
index f475201..00fabfc 100644
--- a/readme.md
+++ b/readme.md
@@ -1,23 +1,30 @@
-[Github API](https://developer.github.com/v3/) easy access library. Works with cURL, stream or any of your HTTP client.
+[GitHub API](https://developer.github.com/v3/) Easy Access library
+==================================================================
 
-[![Build Status](https://travis-ci.org/milo/github-api.svg?branch=master)](https://travis-ci.org/milo/github-api)
-[![Downloads last 30 days](https://img.shields.io/packagist/dm/milo/github-api.svg)](https://packagist.org/packages/milo/github-api)
+Works with cURL, stream or any of your HTTP client.
 
+[![Downloads this Month](https://img.shields.io/packagist/dm/milo/github-api.svg)](https://packagist.org/packages/milo/github-api)
+[![Tests](https://github.com/milo/github-api/actions/workflows/tests.yml/badge.svg?branch=master)](https://github.com/milo/github-api/actions)
 
-# Installation
+
+Installation
+------------
 Download [release](https://github.com/milo/github-api/releases), decompress and include `github-api.php` manually, or use [Composer](https://getcomposer.org/):
+
 ```
 composer require milo/github-api
 ```
 
 
-# Documentation
+Documentation
+-------------
 Everything at [wiki pages](https://github.com/milo/github-api/wiki), including the [short classes description](https://github.com/milo/github-api/wiki/Classes-description).
 
 
 Quick Start
-===========
-List all emojis used on Github.
+-----------
+List all emojis used on GitHub.
+
 ```php
 use Milo\Github;
 
@@ -41,7 +48,8 @@ stdClass Object (
 ```
 
 
-# License
+License
+-------
 The MIT License (MIT)
 
 Copyright (c) 2014 Miloslav Hůla
diff --git a/src/Github/Api.php b/src/Github/Api.php
index afa6d31..94a0613 100644
--- a/src/Github/Api.php
+++ b/src/Github/Api.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github;
 
 
@@ -10,79 +12,73 @@
  *
  * @author  Miloslav Hůla (https://github.com/milo)
  */
-class Api extends Sanity
+class Api
 {
-	/** @var string */
-	private $url = 'https://api.github.com';
+	use Strict;
+
+	private string $url = 'https://api.github.com';
 
-	/** @var string */
-	private $defaultAccept = 'application/vnd.github.v3+json';
+	private string $defaultAccept = 'application/vnd.github.v3+json';
 
-	/** @var array|NULL */
-	private $defaultParameters = [];
+	private ?array $defaultParameters = [];
 
-	/** @var Http\IClient */
-	private $client;
+	private Http\IClient $client;
 
-	/** @var OAuth\Token|NULL */
-	private $token;
+	private ?OAuth\Token $token = null;
 
 
-	public function __construct(Http\IClient $client = NULL)
+	public function __construct(?Http\IClient $client = null)
 	{
 		$this->client = $client ?: Helpers::createDefaultClient();
 	}
 
 
-	/**
-	 * @return self
-	 */
-	public function setToken(OAuth\Token $token = NULL)
+	public function setToken(?OAuth\Token $token = null): static
 	{
 		$this->token = $token;
 		return $this;
 	}
 
 
-	/**
-	 * @return OAuth\Token|NULL
-	 */
-	public function getToken()
+	public function getToken(): ?OAuth\Token
 	{
 		return $this->token;
 	}
 
 
-	/**
-	 * @param  array
-	 * @return self
-	 */
-	public function setDefaultParameters(array $defaults = NULL)
+	public function setDefaultParameters(?array $defaults = null): static
 	{
 		$this->defaultParameters = $defaults ?: [];
 		return $this;
 	}
 
 
-	/**
-	 * @return array
-	 */
-	public function getDefaultParameters()
+	public function getDefaultParameters(): array
 	{
 		return $this->defaultParameters;
 	}
 
 
+	public function setDefaultAccept(string $accept): self
+	{
+		$this->defaultAccept = $accept;
+		return $this;
+	}
+
+
+	public function getDefaultAccept(): string
+	{
+		return $this->defaultAccept;
+	}
+
+
 	/**
 	 * @see createRequest()
 	 * @see request()
 	 *
-	 * @param  string
-	 * @return Http\Response
-	 *
 	 * @throws MissingParameterException
 	 */
-	public function delete($urlPath, array $parameters = [], array $headers = [])
+	public function delete(string $urlPath, array $parameters = [], array $headers = []): Http\Response
 	{
 		return $this->request(
 			$this->createRequest(Http\Request::DELETE, $urlPath, $parameters, $headers)
@@ -94,12 +90,9 @@ public function delete($urlPath, array $parameters = [], array $headers = [])
 	 * @see createRequest()
 	 * @see request()
 	 *
-	 * @param  string
-	 * @return Http\Response
-	 *
 	 * @throws MissingParameterException
 	 */
-	public function get($urlPath, array $parameters = [], array $headers = [])
+	public function get(string $urlPath, array $parameters = [], array $headers = []): Http\Response
 	{
 		return $this->request(
 			$this->createRequest(Http\Request::GET, $urlPath, $parameters, $headers)
@@ -111,12 +104,9 @@ public function get($urlPath, array $parameters = [], array $headers = [])
 	 * @see createRequest()
 	 * @see request()
 	 *
-	 * @param  string
-	 * @return Http\Response
-	 *
 	 * @throws MissingParameterException
 	 */
-	public function head($urlPath, array $parameters = [], array $headers = [])
+	public function head(string $urlPath, array $parameters = [], array $headers = []): Http\Response
 	{
 		return $this->request(
 			$this->createRequest(Http\Request::HEAD, $urlPath, $parameters, $headers)
@@ -128,14 +118,10 @@ public function head($urlPath, array $parameters = [], array $headers = [])
 	 * @see createRequest()
 	 * @see request()
 	 *
-	 * @param  string
-	 * @param  mixed
-	 * @return Http\Response
-	 *
 	 * @throws MissingParameterException
 	 * @throws JsonException
 	 */
-	public function patch($urlPath, $content, array $parameters = [], array $headers = [])
+	public function patch(string $urlPath, string|array|object|null $content, array $parameters = [], array $headers = []): Http\Response
 	{
 		return $this->request(
 			$this->createRequest(Http\Request::PATCH, $urlPath, $parameters, $headers, $content)
@@ -147,14 +133,10 @@ public function patch($urlPath, $content, array $parameters = [], array $headers
 	 * @see createRequest()
 	 * @see request()
 	 *
-	 * @param  string
-	 * @param  mixed
-	 * @return Http\Response
-	 *
 	 * @throws MissingParameterException
 	 * @throws JsonException
 	 */
-	public function post($urlPath, $content, array $parameters = [], array $headers = [])
+	public function post(string $urlPath, string|array|object|null $content, array $parameters = [], array $headers = []): Http\Response
 	{
 		return $this->request(
 			$this->createRequest(Http\Request::POST, $urlPath, $parameters, $headers, $content)
@@ -166,14 +148,10 @@ public function post($urlPath, $content, array $parameters = [], array $headers
 	 * @see createRequest()
 	 * @see request()
 	 *
-	 * @param  string
-	 * @param  mixed
-	 * @return Http\Response
-	 *
 	 * @throws MissingParameterException
 	 * @throws JsonException
 	 */
-	public function put($urlPath, $content = NULL, array $parameters = [], array $headers = [])
+	public function put(string $urlPath, string|array|object|null $content = null, array $parameters = [], array $headers = []): Http\Response
 	{
 		return $this->request(
 			$this->createRequest(Http\Request::PUT, $urlPath, $parameters, $headers, $content)
@@ -182,11 +160,9 @@ public function put($urlPath, $content = NULL, array $parameters = [], array $he
 
 
 	/**
-	 * @return Http\Response
-	 *
 	 * @throws Http\BadResponseException
 	 */
-	public function request(Http\Request $request)
+	public function request(Http\Request $request): Http\Response
 	{
 		$request = clone $request;
 
@@ -204,31 +180,38 @@ public function request(Http\Request $request)
 
 
 	/**
-	 * @param  string  Http\Request::GET|POST|...
-	 * @param  string  path like '/users/:user/repos' where ':user' is substitution
-	 * @param  array[name => value]  replaces substitutions in $urlPath, the rest is appended as query string to URL
-	 * @param  array[name => value]  name is case-insensitive
-	 * @param  mixed|NULL  arrays and objects are encoded to JSON and Content-Type is set
-	 * @return Http\Request
+	 * @param  string $method  Http\Request::GET|POST|...
+	 * @param  string $urlPath  like '/users/:user/repos' where ':user' is substitution
+	 * @param  string[] $parameters  replaces substitutions in $urlPath, the rest is appended as query string to URL
+	 * @param  string[] $headers  key as case-insensitive header name
+	 * @param  string|array|object|null $content  arrays and objects are encoded to JSON and Content-Type is set
 	 *
 	 * @throws MissingParameterException  when substitution is used in URL but parameter is missing
 	 * @throws JsonException  when encoding to JSON fails
 	 */
-	public function createRequest($method, $urlPath, array $parameters = [], array $headers = [], $content = NULL)
+	public function createRequest(string $method, string $urlPath, array $parameters = [], array $headers = [], string|array|object|null $content = null): Http\Request
 	{
-		if (stripos($urlPath, $this->url) === 0) {
+		if (stripos($urlPath, $this->url) === 0) {  # Allows non-HTTPS URLs
+			$baseUrl = $this->url;
 			$urlPath = substr($urlPath, strlen($this->url));
+
+		} elseif (preg_match('#^(https://[^/]+)(/.*)?$#', $urlPath, $m)) {
+			$baseUrl = $m[1];
+			$urlPath = $m[2] ?? '';
+
+		} else {
+			$baseUrl = $this->url;
 		}
 
-		if (strpos($urlPath, '{') === FALSE) {
+		if (!str_contains($urlPath, '{')) {
 			$urlPath = $this->expandColonParameters($urlPath, $parameters, $this->defaultParameters);
 		} else {
 			$urlPath = $this->expandUriTemplate($urlPath, $parameters, $this->defaultParameters);
 		}
 
-		$url = rtrim($this->url, '/') . '/' . ltrim($urlPath, '/');
+		$url = rtrim($baseUrl, '/') . '/' . ltrim($urlPath, '/');
 
-		if ($content !== NULL && (is_array($content) || is_object($content))) {
+		if (is_array($content) || is_object($content)) {
 			$headers['Content-Type'] = 'application/json; charset=utf-8';
 			$content = Helpers::jsonEncode($content);
 		}
@@ -238,13 +221,11 @@ public function createRequest($method, $urlPath, array $parameters = [], array $
 
 
 	/**
-	 * @param  Http\Response
-	 * @param  array|NULL  these codes are treated as success; code < 300 if NULL
-	 * @return mixed
+	 * @param  ?int[] $okCodes  these codes are treated as success; code < 300 if null
 	 *
 	 * @throws ApiException
 	 */
-	public function decode(Http\Response $response, array $okCodes = NULL)
+	public function decode(Http\Response $response, ?array $okCodes = null): mixed
 	{
 		$content = $response->getContent();
 		if (preg_match('~application/json~i', $response->getHeader('Content-Type', ''))) {
@@ -255,35 +236,35 @@ public function decode(Http\Response $response, array $okCodes = NULL)
 			}
 
 			if (!is_array($content) && !is_object($content)) {
-				throw new InvalidResponseException('Decoded JSON is not an array or object.', 0, NULL, $response);
+				throw new InvalidResponseException('Decoded JSON is not an array or object.', 0, null, $response);
 			}
 		}
 
 		$code = $response->getCode();
-		if (($okCodes === NULL && $code >= 300) || (is_array($okCodes) && !in_array($code, $okCodes))) {
+		if (($okCodes === null && $code >= 300) || (is_array($okCodes) && !in_array($code, $okCodes))) {
 			/** @var $content \stdClass */
 			switch ($code) {
 				case Http\Response::S400_BAD_REQUEST:
-					throw new BadRequestException(self::errorMessage($content), $code, NULL, $response);
+					throw new BadRequestException(self::errorMessage($content), $code, null, $response);
 
 				case Http\Response::S401_UNAUTHORIZED:
-					throw new UnauthorizedException(self::errorMessage($content), $code, NULL, $response);
+					throw new UnauthorizedException(self::errorMessage($content), $code, null, $response);
 
 				case Http\Response::S403_FORBIDDEN:
 					if ($response->getHeader('X-RateLimit-Remaining') === '0') {
-						throw new RateLimitExceedException(self::errorMessage($content), $code, NULL, $response);
+						throw new RateLimitExceedException(self::errorMessage($content), $code, null, $response);
 					}
-					throw new ForbiddenException(self::errorMessage($content), $code, NULL, $response);
+					throw new ForbiddenException(self::errorMessage($content), $code, null, $response);
 
 				case Http\Response::S404_NOT_FOUND:
-					throw new NotFoundException('Resource not found or not authorized to access.', $code, NULL, $response);
+					throw new NotFoundException('Resource not found or not authorized to access.', $code, null, $response);
 
 				case Http\Response::S422_UNPROCESSABLE_ENTITY:
-					throw new UnprocessableEntityException(self::errorMessage($content), $code, NULL, $response);
+					throw new UnprocessableEntityException(self::errorMessage($content), $code, null, $response);
 			}
 
-			$message = $okCodes === NULL ? '< 300' : implode(' or ', $okCodes);
-			throw new UnexpectedResponseException("Expected response with code $message.", $code, NULL, $response);
+			$message = $okCodes === null ? '< 300' : implode(' or ', $okCodes);
+			throw new UnexpectedResponseException("Expected response with code $message.", $code, null, $response);
 		}
 
 		return $content;
@@ -295,12 +276,9 @@ public function decode(Http\Response $response, array $okCodes = NULL)
 	 *
 	 * @see get()
 	 *
-	 * @param  string
-	 * @return Paginator
-	 *
 	 * @throws MissingParameterException
 	 */
-	public function paginator($urlPath, array $parameters = [], array $headers = [])
+	public function paginator(string $urlPath, array $parameters = [], array $headers = []): Paginator
 	{
 		return new Paginator(
 			$this,
@@ -309,46 +287,41 @@ public function paginator($urlPath, array $parameters = [], array $headers = [])
 	}
 
 
-	/**
-	 * @return Http\IClient
-	 */
-	public function getClient()
+	public function getClient(): Http\IClient
 	{
 		return $this->client;
 	}
 
 
-	/**
-	 * @param  string
-	 * @return self
-	 */
-	public function setUrl($url)
+	public function withUrl(string $url): Api
+	{
+		$api = clone $this;
+		$api->setUrl($url);
+		return $api;
+	}
+
+
+	public function setUrl(string $url): static
 	{
 		$this->url = $url;
 		return $this;
 	}
 
 
-	/**
-	 * @return string
-	 */
-	public function getUrl()
+	public function getUrl(): string
 	{
 		return $this->url;
 	}
 
 
 	/**
-	 * @param  string
-	 * @return string
-	 *
 	 * @throws MissingParameterException
 	 */
-	protected function expandColonParameters($url, array $parameters, array $defaultParameters)
+	protected function expandColonParameters(string $url, array $parameters, array $defaultParameters): string
 	{
 		$parameters += $defaultParameters;
 
-		$url = preg_replace_callback('#(^|/):([^/]+)#', function($m) use ($url, & $parameters) {
+		$url = preg_replace_callback('#(^|/|\.):([^/.]+)#', function($m) use ($url, &$parameters) {
 			if (!isset($parameters[$m[2]])) {
 				throw new MissingParameterException("Missing parameter '$m[2]' for URL path '$url'.");
 			}
@@ -372,38 +345,35 @@ protected function expandColonParameters($url, array $parameters, array $default
 	 *
 	 * @see http://tools.ietf.org/html/rfc6570
 	 * @todo Inject remaining default parameters into query string?
-	 *
-	 * @param  string
-	 * @return string
 	 */
-	protected function expandUriTemplate($url, array $parameters, array $defaultParameters)
+	protected function expandUriTemplate(string $url, array $parameters, array $defaultParameters): string
 	{
 		$parameters += $defaultParameters;
 
 		static $operatorFlags = [
-			''  => ['prefix' => '',  'separator' => ',', 'named' => FALSE, 'ifEmpty' => '',  'reserved' => FALSE],
-			'+' => ['prefix' => '',  'separator' => ',', 'named' => FALSE, 'ifEmpty' => '',  'reserved' => TRUE],
-			'#' => ['prefix' => '#', 'separator' => ',', 'named' => FALSE, 'ifEmpty' => '',  'reserved' => TRUE],
-			'.' => ['prefix' => '.', 'separator' => '.', 'named' => FALSE, 'ifEmpty' => '',  'reserved' => FALSE],
-			'/' => ['prefix' => '/', 'separator' => '/', 'named' => FALSE, 'ifEmpty' => '',  'reserved' => FALSE],
-			';' => ['prefix' => ';', 'separator' => ';', 'named' => TRUE,  'ifEmpty' => '',  'reserved' => FALSE],
-			'?' => ['prefix' => '?', 'separator' => '&', 'named' => TRUE,  'ifEmpty' => '=', 'reserved' => FALSE],
-			'&' => ['prefix' => '&', 'separator' => '&', 'named' => TRUE,  'ifEmpty' => '=', 'reserved' => FALSE],
+			''  => ['prefix' => '',  'separator' => ',', 'named' => false, 'ifEmpty' => '',  'reserved' => false],
+			'+' => ['prefix' => '',  'separator' => ',', 'named' => false, 'ifEmpty' => '',  'reserved' => true],
+			'#' => ['prefix' => '#', 'separator' => ',', 'named' => false, 'ifEmpty' => '',  'reserved' => true],
+			'.' => ['prefix' => '.', 'separator' => '.', 'named' => false, 'ifEmpty' => '',  'reserved' => false],
+			'/' => ['prefix' => '/', 'separator' => '/', 'named' => false, 'ifEmpty' => '',  'reserved' => false],
+			';' => ['prefix' => ';', 'separator' => ';', 'named' => true,  'ifEmpty' => '',  'reserved' => false],
+			'?' => ['prefix' => '?', 'separator' => '&', 'named' => true,  'ifEmpty' => '=', 'reserved' => false],
+			'&' => ['prefix' => '&', 'separator' => '&', 'named' => true,  'ifEmpty' => '=', 'reserved' => false],
 		];
 
-		return preg_replace_callback('~{([+#./;?&])?([^}]+?)}~', function($m) use ($url, & $parameters, $operatorFlags) {
+		return preg_replace_callback('~{([+#./;?&])?([^}]+?)}~', function($m) use ($url, &$parameters, $operatorFlags) {
 			$flags = $operatorFlags[$m[1]];
 
 			$translated = [];
 			foreach (explode(',', $m[2]) as $name) {
-				$explode = FALSE;
-				$maxLength = NULL;
+				$explode = false;
+				$maxLength = null;
 				if (preg_match('~^(.+)(?:(\*)|:(\d+))$~', $name, $tmp)) { // TODO: Speed up?
 					$name = $tmp[1];
 					if (isset($tmp[3])) {
 						$maxLength = (int) $tmp[3];
 					} else {
-						$explode = TRUE;
+						$explode = true;
 					}
 				}
 
@@ -420,20 +390,20 @@ protected function expandUriTemplate($url, array $parameters, array $defaultPara
 					$isAssoc = key($value) !== 0;
 
 					// The '*' (explode) modifier
+					$parts = [];
 					if ($explode) {
-						$parts = [];
 						if ($isAssoc) {
-							$this->walk($value, function ($v, $k) use (& $parts, $flags, $maxLength) {
-								$parts[] = $this->prefix(['named' => TRUE] + $flags, $k, $this->escape($flags, $v, $maxLength));
+							$this->walk($value, function ($v, $k) use (&$parts, $flags, $maxLength) {
+								$parts[] = $this->prefix(['named' => true] + $flags, $k, $this->escape($flags, $v, $maxLength));
 							});
 
 						} elseif ($flags['named']) {
-							$this->walk($value, function ($v) use (& $parts, $flags, $name, $maxLength) {
+							$this->walk($value, function ($v) use (&$parts, $flags, $name, $maxLength) {
 								$parts[] = $this->prefix($flags, $name, $this->escape($flags, $v, $maxLength));
 							});
 
 						} else {
-							$this->walk($value, function ($v) use (& $parts, $flags, $maxLength) {
+							$this->walk($value, function ($v) use (&$parts, $flags, $maxLength) {
 								$parts[] = $this->escape($flags, $v, $maxLength);
 							});
 						}
@@ -447,8 +417,7 @@ protected function expandUriTemplate($url, array $parameters, array $defaultPara
 						}
 
 					} else {
-						$parts = [];
-						$this->walk($value, function($v, $k) use (& $parts, $isAssoc, $flags, $maxLength) {
+						$this->walk($value, function($v, $k) use (&$parts, $isAssoc, $flags, $maxLength) {
 							if ($isAssoc) {
 								$parts[] = $this->escape($flags, $k);
 							}
@@ -473,12 +442,9 @@ protected function expandUriTemplate($url, array $parameters, array $defaultPara
 
 
 	/**
-	 * @param  array
-	 * @param  string
-	 * @param  string  already escaped
-	 * @return string
+	 * @param  string $value  already escaped
 	 */
-	private function prefix(array $flags, $name, $value)
+	private function prefix(array $flags, string $name, string $value): string
 	{
 		$prefix = '';
 		if ($flags['named']) {
@@ -494,17 +460,11 @@ private function prefix(array $flags, $name, $value)
 	}
 
 
-	/**
-	 * @param  array
-	 * @param  mixed
-	 * @param  int|NULL
-	 * @return string
-	 */
-	private function escape(array $flags, $value, $maxLength = NULL)
+	private function escape(array $flags, string|int|false $value, ?int $maxLength = null): string
 	{
 		$value = (string) $value;
 
-		if ($maxLength !== NULL) {
+		if ($maxLength !== null) {
 			if (preg_match('~^(.{' . $maxLength . '}).~u', $value, $m)) {
 				$value = $m[1];
 			} elseif (strlen($value) > $maxLength) {  # when malformed UTF-8
@@ -528,14 +488,10 @@ private function escape(array $flags, $value, $maxLength = NULL)
 	}
 
 
-	/**
-	 * @param  array
-	 * @param  callable
-	 */
-	private function walk(array $array, $cb)
+	private function walk(array $array, callable $cb): void
 	{
 		foreach ($array as $k => $v) {
-			if ($v === NULL) {
+			if ($v === null) {
 				continue;
 			}
 
@@ -544,15 +500,9 @@ private function walk(array $array, $cb)
 	}
 
 
-	/**
-	 * @param  \stdClass
-	 * @return string
-	 */
-	private static function errorMessage($content)
+	private static function errorMessage(\stdClass $content): string
 	{
-		$message = isset($content->message)
-			? $content->message
-			: 'Unknown error';
+		$message = $content->message ?? 'Unknown error';
 
 		if (isset($content->errors)) {
 			$message .= implode(', ', array_map(function($error) {
@@ -562,5 +512,4 @@ private static function errorMessage($content)
 
 		return $message;
 	}
-
 }
diff --git a/src/Github/Helpers.php b/src/Github/Helpers.php
index 1346dc3..9b22d7a 100644
--- a/src/Github/Helpers.php
+++ b/src/Github/Helpers.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github;
 
 
@@ -13,83 +15,38 @@
  */
 class Helpers
 {
-	private static $jsonMessages = [
-		JSON_ERROR_DEPTH => 'The maximum stack depth has been exceeded',
-		JSON_ERROR_STATE_MISMATCH => 'Syntax error, malformed JSON',
-		JSON_ERROR_CTRL_CHAR => 'Unexpected control character found',
-		JSON_ERROR_SYNTAX => 'Syntax error, malformed JSON',
-		JSON_ERROR_UTF8 => 'Invalid UTF-8 sequence',
-	];
-
-
-	/** @var Http\IClient */
-	private static $client;
+	private static Http\IClient $client;
 
 
 	/**
-	 * @param  mixed
-	 * @return string
-	 *
 	 * @throws JsonException
 	 */
-	public static function jsonEncode($value)
+	public static function jsonEncode(mixed $value): string
 	{
-		if (PHP_VERSION_ID < 50500) {
-			set_error_handler(function($severity, $message) { // needed to receive 'recursion detected' error
-				restore_error_handler();
-				throw new JsonException($message);
-			});
-		}
-
 		$json = json_encode($value, JSON_UNESCAPED_UNICODE);
-
-		if (PHP_VERSION_ID < 50500) {
-			restore_error_handler();
-		}
-
 		if ($error = json_last_error()) {
-			$message = isset(static::$jsonMessages[$error])
-				? static::$jsonMessages[$error]
-				: (PHP_VERSION_ID >= 50500 ? json_last_error_msg() : 'Unknown error');
-
-			throw new JsonException($message, $error);
+			throw new JsonException(json_last_error_msg(), $error);
 		}
-
-		$json = str_replace(array("\xe2\x80\xa8", "\xe2\x80\xa9"), array('\u2028', '\u2029'), $json);
 		return $json;
 	}
 
 
 	/**
-	 * @param  mixed
-	 * @return string
-	 *
 	 * @throws JsonException
 	 */
-	public static function jsonDecode($json)
+	public static function jsonDecode(string $json): mixed
 	{
-		$json = (string) $json;
-		if (!preg_match('##u', $json)) {
-			throw new JsonException('Invalid UTF-8 sequence', 5); // PECL JSON-C
-		}
-
-		$value = json_decode($json, FALSE, 512, (defined('JSON_C_VERSION') && PHP_INT_SIZE > 4) ? 0 : JSON_BIGINT_AS_STRING);
-
-		if ($value === NULL && $json !== '' && strcasecmp($json, 'null')) { // '' does not clear json_last_error()
-			$error = json_last_error();
-			throw new JsonException(isset(static::$jsonMessages[$error]) ? static::$jsonMessages[$error] : 'Unknown error', $error);
+		$value = json_decode($json, false, 512, JSON_BIGINT_AS_STRING);
+		if ($error = json_last_error()) {
+			throw new JsonException(json_last_error_msg(), $error);
 		}
 		return $value;
 	}
 
 
-	/**
-	 * @param  bool
-	 * @return Http\IClient
-	 */
-	public static function createDefaultClient($newInstance = FALSE)
+	public static function createDefaultClient(bool $newInstance = false): Http\IClient
 	{
-		if (self::$client === NULL || $newInstance) {
+		if (empty(self::$client) || $newInstance) {
 			self::$client = extension_loaded('curl')
 				? new Http\CurlClient
 				: new Http\StreamClient;
@@ -97,5 +54,4 @@ public static function createDefaultClient($newInstance = FALSE)
 
 		return self::$client;
 	}
-
 }
diff --git a/src/Github/Http/AbstractClient.php b/src/Github/Http/AbstractClient.php
index 5cd036d..fd1644d 100644
--- a/src/Github/Http/AbstractClient.php
+++ b/src/Github/Http/AbstractClient.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github\Http;
 
 use Milo\Github;
@@ -10,38 +12,38 @@
  *
  * @author  Miloslav Hůla (https://github.com/milo)
  */
-abstract class AbstractClient extends Github\Sanity implements IClient
+abstract class AbstractClient implements IClient
 {
+	use Github\Strict;
+
 	/** @var int[]  will follow Location header on these response codes */
-	public $redirectCodes = [
+	public array $redirectCodes = [
 		Response::S301_MOVED_PERMANENTLY,
 		Response::S302_FOUND,
 		Response::S307_TEMPORARY_REDIRECT,
 	];
 
-	/** @var int  maximum redirects per request*/
-	public $maxRedirects = 5;
+	/** Maximum redirects per request */
+	public int $maxRedirects = 5;
 
-	/** @var callable|NULL */
+	/** @var callable|null */
 	private $onRequest;
 
-	/** @var callable|NULL */
+	/** @var callable|null */
 	private $onResponse;
 
 
 	/**
 	 * @see https://developer.github.com/v3/#http-redirects
 	 *
-	 * @return Response
-	 *
 	 * @throws BadResponseException
 	 */
-	public function request(Request $request)
+	public function request(Request $request): Response
 	{
 		$request = clone $request;
 
 		$counter = $this->maxRedirects;
-		$previous = NULL;
+		$previous = null;
 		do {
 			$this->setupRequest($request);
 
@@ -65,45 +67,36 @@ public function request(Request $request)
 			}
 			break;
 
-		} while (TRUE);
+		} while (true);
 
 		return $response;
 	}
 
 
-	/**
-	 * @param  callable|NULL function(Request $request)
-	 * @return self
-	 */
-	public function onRequest($callback)
+	/** @inheritdoc */
+	public function onRequest(?callable $callback): static
 	{
 		$this->onRequest = $callback;
 		return $this;
 	}
 
 
-	/**
-	 * @param  callable|NULL function(Response $response)
-	 * @return self
-	 */
-	public function onResponse($callback)
+	/** @inheritdoc */
+	public function onResponse(?callable $callback): static
 	{
 		$this->onResponse = $callback;
 		return $this;
 	}
 
 
-	protected function setupRequest(Request $request)
+	protected function setupRequest(Request $request): void
 	{
 		$request->addHeader('Expect', '');
 	}
 
 
 	/**
-	 * @return Response
-	 *
 	 * @throws BadResponseException
 	 */
-	abstract protected function process(Request $request);
-
+	abstract protected function process(Request $request): Response;
 }
diff --git a/src/Github/Http/CachedClient.php b/src/Github/Http/CachedClient.php
index f7c5f85..967df83 100644
--- a/src/Github/Http/CachedClient.php
+++ b/src/Github/Http/CachedClient.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github\Http;
 
 use Milo\Github;
@@ -11,49 +13,38 @@
  *
  * @author  Miloslav Hůla (https://github.com/milo)
  */
-class CachedClient extends Github\Sanity implements IClient
+class CachedClient implements IClient
 {
-	/** @var Storages\ICache|NULL */
-	private $cache;
-
-	/** @var IClient */
-	private $client;
+	use Github\Strict;
 
-	/** @var bool */
-	private $forbidRecheck;
+	private IClient $client;
 
-	/** @var callable|NULL */
+	/** @var ?callable(Response $response): void */
 	private $onResponse;
 
 
 	/**
-	 * @param Storages\ICache
-	 * @param IClient
-	 * @param bool  forbid checking Github for new data; more or less development purpose only
+	 * @param  bool $forbidRecheck  Forbid checking GitHub for new data; more or less development purpose only
 	 */
-	public function __construct(Storages\ICache $cache, IClient $client = NULL, $forbidRecheck = FALSE)
-	{
-		$this->cache = $cache;
+	public function __construct(
+		private Storages\ICache $cache,
+		?IClient $client = null,
+		private bool $forbidRecheck = false,
+	) {
 		$this->client = $client ?: Github\Helpers::createDefaultClient();
-		$this->forbidRecheck = (bool) $forbidRecheck;
 	}
 
 
-	/**
-	 * @return IClient
-	 */
-	public function getInnerClient()
+	public function getInnerClient(): IClient
 	{
 		return $this->client;
 	}
 
 
 	/**
-	 * @return Response
-	 *
 	 * @throws BadResponseException
 	 */
-	public function request(Request $request)
+	public function request(Request $request): Response
 	{
 		$request = clone $request;
 
@@ -77,7 +68,8 @@ public function request(Request $request)
 			/** @var $cached Response */
 			if ($cached->hasHeader('Last-Modified')) {
 				$request->addHeader('If-Modified-Since', $cached->getHeader('Last-Modified'));
-			} elseif ($cached->hasHeader('ETag')) {
+			}
+			if ($cached->hasHeader('ETag')) {
 				$request->addHeader('If-None-Match', $cached->getHeader('ETag'));
 			}
 		}
@@ -101,42 +93,33 @@ public function request(Request $request)
 	}
 
 
-	/**
-	 * @param  callable|NULL function(Request $request)
-	 * @return self
-	 */
-	public function onRequest($callback)
+	/** @inheritdoc */
+	public function onRequest(?callable $callback): static
 	{
 		$this->client->onRequest($callback);
 		return $this;
 	}
 
 
-	/**
-	 * @param  callable|NULL function(Response $response)
-	 * @return self
-	 */
-	public function onResponse($callback)
+	/** @inheritdoc */
+	public function onResponse(?callable $callback): static
 	{
-		$this->client->onResponse(NULL);
+		$this->client->onResponse(null);
 		$this->onResponse = $callback;
 		return $this;
 	}
 
 
-	/**
-	 * @return bool
-	 */
-	protected function isCacheable(Response $response)
+	protected function isCacheable(Response $response): bool
 	{
 		/** @todo Do it properly. Vary:, Pragma:, TTL...  */
 		if (!$response->isCode(200)) {
-			return FALSE;
+			return false;
+
 		} elseif (preg_match('#max-age=0|must-revalidate#i', $response->getHeader('Cache-Control', ''))) {
-			return FALSE;
+			return false;
 		}
 
 		return $response->hasHeader('ETag') || $response->hasHeader('Last-Modified');
 	}
-
 }
diff --git a/src/Github/Http/CurlClient.php b/src/Github/Http/CurlClient.php
index 06d3d06..0b072c3 100644
--- a/src/Github/Http/CurlClient.php
+++ b/src/Github/Http/CurlClient.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github\Http;
 
 use Milo\Github;
@@ -12,29 +14,24 @@
  */
 class CurlClient extends AbstractClient
 {
-	/** @var array|NULL */
-	private $options;
-
 	/** @var resource */
 	private $curl;
 
 
 	/**
-	 * @param  array  cURL options {@link http://php.net/manual/en/function.curl-setopt.php}
-	 *
+	 * @param  ?array $options  cURL options {@link http://php.net/manual/en/function.curl-setopt.php}
 	 * @throws Github\LogicException
 	 */
-	public function __construct(array $options = NULL)
-	{
+	public function __construct(
+		private ?array $options = null,
+	) {
 		if (!extension_loaded('curl')) {
 			throw new Github\LogicException('cURL extension is not loaded.');
 		}
-
-		$this->options = $options;
 	}
 
 
-	protected function setupRequest(Request $request)
+	protected function setupRequest(Request $request): void
 	{
 		parent::setupRequest($request);
 		$request->addHeader('Connection', 'keep-alive');
@@ -42,11 +39,9 @@ protected function setupRequest(Request $request)
 
 
 	/**
-	 * @return Response
-	 *
 	 * @throws BadResponseException
 	 */
-	protected function process(Request $request)
+	protected function process(Request $request): Response
 	{
 		$headers = [];
 		foreach ($request->getHeaders() as $name => $value) {
@@ -63,26 +58,26 @@ protected function process(Request $request)
 		];
 
 		$hardOptions = [
-			CURLOPT_FOLLOWLOCATION => FALSE, # Github sets the Location header for 201 code too and redirection is not required for us
+			CURLOPT_FOLLOWLOCATION => false, # Github sets the Location header for 201 code too and redirection is not required for us
 			CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
 			CURLOPT_CUSTOMREQUEST => $request->getMethod(),
 			CURLOPT_NOBODY => $request->isMethod(Request::HEAD),
 			CURLOPT_URL => $request->getUrl(),
 			CURLOPT_HTTPHEADER => $headers,
-			CURLOPT_RETURNTRANSFER => TRUE,
+			CURLOPT_RETURNTRANSFER => true,
 			CURLOPT_POSTFIELDS => $request->getContent(),
-			CURLOPT_HEADER => FALSE,
-			CURLOPT_HEADERFUNCTION => function($curl, $line) use (& $responseHeaders, & $last) {
+			CURLOPT_HEADER => false,
+			CURLOPT_HEADERFUNCTION => function($curl, $line) use (&$responseHeaders, &$last) {
 				if (strncasecmp($line, 'HTTP/', 5) === 0) {
 					/** @todo Set proxy response as Response::setPrevious($proxyResponse)? */
 					# The HTTP/x.y may occur multiple times with proxy (HTTP/1.1 200 Connection Established)
 					$responseHeaders = [];
 
-				} elseif (in_array(substr($line, 0, 1), [' ', "\t"], TRUE)) {
+				} elseif (in_array(substr($line, 0, 1), [' ', "\t"], true)) {
 					$responseHeaders[$last] .= ' ' . trim($line);  # RFC2616, 2.2
 
 				} elseif ($line !== "\r\n") {
-					list($name, $value) = explode(':', $line, 2);
+					[$name, $value] = explode(':', $line, 2);
 					$responseHeaders[$last = trim($name)] = trim($value);
 				}
 
@@ -96,27 +91,26 @@ protected function process(Request $request)
 
 		if (!$this->curl) {
 			$this->curl = curl_init();
-			if ($this->curl === FALSE) {
+			if ($this->curl === false) {
 				throw new BadResponseException('Cannot init cURL handler.');
 			}
 		}
 
 		$result = curl_setopt_array($this->curl, $hardOptions + ($this->options ?: []) + $softOptions);
-		if ($result === FALSE) {
+		if ($result === false) {
 			throw new BadResponseException('Setting cURL options failed: ' . curl_error($this->curl), curl_errno($this->curl));
 		}
 
 		$content = curl_exec($this->curl);
-		if ($content === FALSE) {
+		if ($content === false) {
 			throw new BadResponseException(curl_error($this->curl), curl_errno($this->curl));
 		}
 
 		$code = curl_getinfo($this->curl, CURLINFO_HTTP_CODE);
-		if ($code === FALSE) {
+		if ($code === false) {
 			throw new BadResponseException('HTTP status code is missing:' . curl_error($this->curl), curl_errno($this->curl));
 		}
 
-		return new Response($code, $responseHeaders, $content);
+		return new Response((int) $code, $responseHeaders, $content);
 	}
-
 }
diff --git a/src/Github/Http/IClient.php b/src/Github/Http/IClient.php
index 966cd75..4d61917 100644
--- a/src/Github/Http/IClient.php
+++ b/src/Github/Http/IClient.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github\Http;
 
 
@@ -10,21 +12,15 @@
  */
 interface IClient
 {
-	/**
-	 * @return Response
-	 */
-	function request(Request $request);
+	function request(Request $request): Response;
 
 	/**
-	 * @param  callable|NULL
-	 * @return self
+	 * @param ?callable(Request $request): void  $callback
 	 */
-	function onRequest($callback);
+	function onRequest(?callable $callback): static;
 
 	/**
-	 * @param  callable|NULL
-	 * @return self
+	 * @param ?callable(Response $response): void  $callback
 	 */
-	function onResponse($callback);
-
+	function onResponse(?callable $callback): static;
 }
diff --git a/src/Github/Http/Message.php b/src/Github/Http/Message.php
index c8b740e..089c548 100644
--- a/src/Github/Http/Message.php
+++ b/src/Github/Http/Message.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github\Http;
 
 use Milo\Github;
@@ -10,42 +12,30 @@
  *
  * @author  Miloslav Hůla (https://github.com/milo)
  */
-abstract class Message extends Github\Sanity
+abstract class Message
 {
-	/** @var array[name => value] */
-	private $headers = [];
+	use Github\Strict;
 
-	/** @var string|NULL */
-	private $content;
+	private array $headers = [];
 
 
-	/**
-	 * @param  array
-	 * @param  string|NULL
-	 */
-	public function __construct(array $headers = [], $content = NULL)
-	{
-		$this->headers = array_change_key_case($headers, CASE_LOWER);
-		$this->content = $content;
+	public function __construct(
+		array $headers = [],
+		private ?string $content = null,
+	) {
+		foreach ($headers as $name => $value) {
+			$this->setHeader($name, $value);
+		}
 	}
 
 
-	/**
-	 * @param  string
-	 * @return bool
-	 */
-	public function hasHeader($name)
+	public function hasHeader(string $name): bool
 	{
 		return array_key_exists(strtolower($name), $this->headers);
 	}
 
 
-	/**
-	 * @param  string
-	 * @param  mixed
-	 * @return mixed
-	 */
-	public function getHeader($name, $default = NULL)
+	public function getHeader(string $name, ?string $default = null): ?string
 	{
 		$name = strtolower($name);
 		return array_key_exists($name, $this->headers)
@@ -54,15 +44,10 @@ public function getHeader($name, $default = NULL)
 	}
 
 
-	/**
-	 * @param  string
-	 * @param  string
-	 * @return self
-	 */
-	protected function addHeader($name, $value)
+	protected function addHeader(string $name, ?string $value): static
 	{
 		$name = strtolower($name);
-		if (!array_key_exists($name, $this->headers) && $value !== NULL) {
+		if (!array_key_exists($name, $this->headers) && $value !== null) {
 			$this->headers[$name] = $value;
 		}
 
@@ -70,15 +55,10 @@ protected function addHeader($name, $value)
 	}
 
 
-	/**
-	 * @param  string
-	 * @param  string|NULL
-	 * @return self
-	 */
-	protected function setHeader($name, $value)
+	protected function setHeader(string $name, ?string $value): static
 	{
 		$name = strtolower($name);
-		if ($value === NULL) {
+		if ($value === null) {
 			unset($this->headers[$name]);
 		} else {
 			$this->headers[$name] = $value;
@@ -89,20 +69,16 @@ protected function setHeader($name, $value)
 
 
 	/**
-	 * @return array
+	 * @return string[]
 	 */
-	public function getHeaders()
+	public function getHeaders(): array
 	{
 		return $this->headers;
 	}
 
 
-	/**
-	 * @return string|NULL
-	 */
-	public function getContent()
+	public function getContent(): ?string
 	{
 		return $this->content;
 	}
-
 }
diff --git a/src/Github/Http/Request.php b/src/Github/Http/Request.php
index 9391c61..4ac0207 100644
--- a/src/Github/Http/Request.php
+++ b/src/Github/Http/Request.php
@@ -1,8 +1,8 @@
 <?php
 
-namespace Milo\Github\Http;
+declare(strict_types=1);
 
-use Milo\Github;
+namespace Milo\Github\Http;
 
 
 /**
@@ -13,7 +13,7 @@
 class Request extends Message
 {
 	/** HTTP request method */
-	const
+	public const
 		DELETE = 'DELETE',
 		GET = 'GET',
 		HEAD = 'HEAD',
@@ -22,74 +22,42 @@ class Request extends Message
 		PUT = 'PUT';
 
 
-	/** @var string */
-	private $method;
-
-	/** @var string */
-	private $url;
-
-
-	/**
-	 * @param  string
-	 * @param  string
-	 * @param  array
-	 * @param  string|NULL
-	 */
-	public function __construct($method, $url, array $headers = [], $content = NULL)
-	{
-		$this->method = $method;
-		$this->url = $url;
+	public function __construct(
+		private string $method,
+		private string $url,
+		array $headers = [],
+		?string $content = null
+	) {
 		parent::__construct($headers, $content);
 	}
 
 
-	/**
-	 * @param  string
-	 * @return bool
-	 */
-	public function isMethod($method)
+	public function isMethod(string $method): bool
 	{
 		return strcasecmp($this->method, $method) === 0;
 	}
 
 
-	/**
-	 * @return string
-	 */
-	public function getMethod()
+	public function getMethod(): string
 	{
 		return $this->method;
 	}
 
 
-	/**
-	 * @return string
-	 */
-	public function getUrl()
+	public function getUrl(): string
 	{
 		return $this->url;
 	}
 
 
-	/**
-	 * @param  string
-	 * @param  string
-	 * @return self
-	 */
-	public function addHeader($name, $value)
+	public function addHeader(string $name, ?string $value): static
 	{
 		return parent::addHeader($name, $value);
 	}
 
 
-	/**
-	 * @param  string
-	 * @param  string|NULL
-	 * @return self
-	 */
-	public function setHeader($name, $value)
+	public function setHeader(string $name, ?string $value): static
 	{
 		return parent::setHeader($name, $value);
 	}
-
 }
diff --git a/src/Github/Http/Response.php b/src/Github/Http/Response.php
index 8d20c26..be602a4 100644
--- a/src/Github/Http/Response.php
+++ b/src/Github/Http/Response.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github\Http;
 
 use Milo\Github;
@@ -13,7 +15,7 @@
 class Response extends Message
 {
 	/** HTTP 1.1 code */
-	const
+	public const
 		S200_OK = 200,
 		S301_MOVED_PERMANENTLY = 301,
 		S302_FOUND = 302,
@@ -25,60 +27,43 @@ class Response extends Message
 		S404_NOT_FOUND = 404,
 		S422_UNPROCESSABLE_ENTITY = 422;
 
-	/** @var int */
-	private $code;
-
-	/** @var Response */
-	private $previous;
+	private ?Response $previous = null;
 
 
-	/**
-	 * @param  int
-	 * @param  array
-	 * @param  string
-	 */
-	public function __construct($code, array $headers, $content)
-	{
-		$this->code = (int) $code;
+	public function __construct(
+		private int $code,
+		array $headers,
+		?string $content,
+	) {
 		parent::__construct($headers, $content);
 	}
 
 
 	/**
-	 * HTTP code.
-	 * @return int
+	 * HTTP response status code.
 	 */
-	public function getCode()
+	public function getCode(): int
 	{
 		return $this->code;
 	}
 
 
-	/**
-	 * @param  int
-	 * @return bool
-	 */
-	public function isCode($code)
+	public function isCode(int $code): bool
 	{
-		return $this->code === (int) $code;
+		return $this->code === $code;
 	}
 
 
-	/**
-	 * @return Response|NULL
-	 */
-	public function getPrevious()
+	public function getPrevious(): ?Response
 	{
 		return $this->previous;
 	}
 
 
 	/**
-	 * @return self
-	 *
 	 * @throws Github\LogicException
 	 */
-	public function setPrevious(Response $previous = NULL)
+	public function setPrevious(?Response $previous = null): static
 	{
 		if ($this->previous) {
 			throw new Github\LogicException('Previous response is already set.');
@@ -87,5 +72,4 @@ public function setPrevious(Response $previous = NULL)
 
 		return $this;
 	}
-
 }
diff --git a/src/Github/Http/StreamClient.php b/src/Github/Http/StreamClient.php
index dbf3b73..f345d17 100644
--- a/src/Github/Http/StreamClient.php
+++ b/src/Github/Http/StreamClient.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github\Http;
 
 
@@ -10,20 +12,15 @@
  */
 class StreamClient extends AbstractClient
 {
-	/** @var array|NULL */
-	private $sslOptions;
-
-
 	/**
-	 * @param  array  SSL context options {@link http://php.net/manual/en/context.ssl.php}
+	 * @param  ?array $sslOptions  SSL context options {@link http://php.net/manual/en/context.ssl.php}
 	 */
-	public function __construct(array $sslOptions = NULL)
-	{
-		$this->sslOptions = $sslOptions;
-	}
+	public function __construct(
+		private ?array $sslOptions = null,
+	) {}
 
 
-	protected function setupRequest(Request $request)
+	protected function setupRequest(Request $request): void
 	{
 		parent::setupRequest($request);
 		$request->setHeader('Connection', 'close');
@@ -31,11 +28,9 @@ protected function setupRequest(Request $request)
 
 
 	/**
-	 * @return Response
-	 *
 	 * @throws BadResponseException
 	 */
-	protected function process(Request $request)
+	protected function process(Request $request): Response
 	{
 		$headerStr = [];
 		foreach ($request->getHeaders() as $name => $value) {
@@ -50,16 +45,16 @@ protected function process(Request $request)
 				'header' => implode("\r\n", $headerStr) . "\r\n",
 				'follow_location' => 0,  # Github sets the Location header for 201 code too and redirection is not required for us
 				'protocol_version' => 1.1,
-				'ignore_errors' => TRUE,
+				'ignore_errors' => true,
 			],
 			'ssl' => [
-				'verify_peer' => TRUE,
+				'verify_peer' => true,
 				'cafile' => realpath(__DIR__ . '/../../ca-chain.crt'),
-				'disable_compression' => TRUE,  # Effective since PHP 5.4.13
+				'disable_compression' => true,  # Effective since PHP 5.4.13
 			],
 		];
 
-		if (($content = $request->getContent()) !== NULL) {
+		if (($content = $request->getContent()) !== null) {
 			$options['http']['content'] = $content;
 		}
 
@@ -67,31 +62,30 @@ protected function process(Request $request)
 			$options['ssl'] = $this->sslOptions + $options['ssl'];
 		}
 
-		list($code, $headers, $content) = $this->fileGetContents($request->getUrl(), $options);
+		[$code, $headers, $content] = $this->fileGetContents($request->getUrl(), $options);
 		return new Response($code, $headers, $content);
 	}
 
 
 	/**
 	 * @internal
-	 * @param  string
-	 * @param  array
-	 * @return array
-	 *
 	 * @throws BadResponseException
 	 */
-	protected function fileGetContents($url, array $contextOptions)
+	protected function fileGetContents(string $url, array $contextOptions): array
 	{
 		$context = stream_context_create($contextOptions);
 
-		$e = NULL;
-		set_error_handler(function($severity, $message, $file, $line) use (& $e) {
+		$e = null;
+		set_error_handler(function($severity, $message, $file, $line) use (&$e) {
 			$e = new \ErrorException($message, 0, $severity, $file, $line, $e);
 		}, E_WARNING);
 
-		$content = file_get_contents($url, FALSE, $context);
+		$content = file_get_contents($url, false, $context);
 		restore_error_handler();
 
+		if (PHP_VERSION_ID >= 80400) {
+			$http_response_header = http_get_last_response_headers();
+		}
 		if (!isset($http_response_header)) {
 			throw new BadResponseException('Missing HTTP headers, request failed.', 0, $e);
 		}
@@ -101,17 +95,17 @@ protected function fileGetContents($url, array $contextOptions)
 		}
 		unset($http_response_header[0]);
 
+		$last = null;
 		$headers = [];
 		foreach ($http_response_header as $header) {
-			if (in_array(substr($header, 0, 1), [' ', "\t"], TRUE)) {
+			if (in_array(substr($header, 0, 1), [' ', "\t"], true)) {
 				$headers[$last] .= ' ' . trim($header);  # RFC2616, 2.2
 			} else {
-				list($name, $value) = explode(':', $header, 2) + [NULL, NULL];
+				[$name, $value] = explode(':', $header, 2) + [null, null];
 				$headers[$last = trim($name)] = trim($value);
 			}
 		}
 
-		return [$m[1], $headers, $content];
+		return [(int) $m[1], $headers, $content];
 	}
-
 }
diff --git a/src/Github/OAuth/Configuration.php b/src/Github/OAuth/Configuration.php
index e5ae7cd..2bd8c59 100644
--- a/src/Github/OAuth/Configuration.php
+++ b/src/Github/OAuth/Configuration.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github\OAuth;
 
 use Milo\Github;
@@ -10,37 +12,27 @@
  *
  * @author  Miloslav Hůla (https://github.com/milo)
  */
-class Configuration extends Github\Sanity
+class Configuration
 {
-	/** @var string */
-	public $clientId;
-
-	/** @var string */
-	public $clientSecret;
-
-	/** @var string[] */
-	public $scopes;
+	use Github\Strict;
 
 
 	/**
-	 * @param  string
-	 * @param  string
-	 * @param  string[]
+	 * @param  string[] $scopes
 	 */
-	public function __construct($clientId, $clientSecret, array $scopes = [])
-	{
-		$this->clientId = $clientId;
-		$this->clientSecret = $clientSecret;
-		$this->scopes = $scopes;
-    }
+	public function __construct(
+		public string $clientId,
+		public string $clientSecret,
+		public array $scopes = [],
+	) {}
 
 
-	/**
-	 * @return Configuration
-	 */
-	public static function fromArray(array $conf)
+	public static function fromArray(array $conf): static
 	{
-		return new static($conf['clientId'], $conf['clientSecret'], isset($conf['scopes']) ? $conf['scopes'] : []);
+		return new static(
+			$conf['clientId'],
+			$conf['clientSecret'],
+			$conf['scopes'] ?? [],
+		);
 	}
-
 }
diff --git a/src/Github/OAuth/Login.php b/src/Github/OAuth/Login.php
index 4e0fac1..7a8b9da 100644
--- a/src/Github/OAuth/Login.php
+++ b/src/Github/OAuth/Login.php
@@ -1,10 +1,12 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github\OAuth;
 
 use Milo\Github;
-use Milo\Github\Storages;
 use Milo\Github\Http;
+use Milo\Github\Storages;
 
 
 /**
@@ -12,49 +14,43 @@
  *
  * @author  Miloslav Hůla (https://github.com/milo)
  */
-class Login extends Github\Sanity
+class Login
 {
-	/** @var string */
-	private $authUrl = 'https://github.com/login/oauth/authorize';
+	use Github\Strict;
 
-	/** @var string */
-	private $tokenUrl = 'https://github.com/login/oauth/access_token';
+	private string $authUrl = 'https://github.com/login/oauth/authorize';
 
-	/** @var Configuration */
-	private $conf;
+	private string $tokenUrl = 'https://github.com/login/oauth/access_token';
 
-	/** @var Storages\ISessionStorage */
-	private $storage;
+	private Storages\SessionStorage|Storages\ISessionStorage $storage;
 
-	/** @var Http\IClient */
-	private $client;
+	private Http\IClient $client;
 
 
-	public function __construct(Configuration $conf, Storages\ISessionStorage $storage = NULL, Http\IClient $client = NULL)
-	{
-		$this->conf = $conf;
+	public function __construct(
+		private Configuration $conf,
+		?Storages\ISessionStorage $storage = null,
+		?Http\IClient $client = null
+	) {
 		$this->storage = $storage ?: new Storages\SessionStorage;
 		$this->client = $client ?: Github\Helpers::createDefaultClient();
 	}
 
 
-	/**
-	 * @return Http\IClient
-	 */
-	public function getClient()
+	public function getClient(): Http\IClient
 	{
 		return $this->client;
 	}
 
 
 	/**
-	 * @param  string  URL to redirect back from Github when user approves the permissions request
-	 * @param  callable function($githubUrl)  makes HTTP redirect to Github
+	 * @param  string $backUrl  URL to redirect back from GitHub when user approves the permissions request
+	 * @param  ?callable $redirectCb  makes HTTP redirect to GitHub
 	 */
-	public function askPermissions($backUrl, $redirectCb = NULL)
+	public function askPermissions(string $backUrl, ?callable $redirectCb = null): void
 	{
 		/** @todo Something more safe? */
-		$state = sha1(uniqid(microtime(TRUE), TRUE));
+		$state = sha1(uniqid((string) microtime(true), true));
 		$params = [
 			'client_id' => $this->conf->clientId,
 			'redirect_uri' => $backUrl,
@@ -65,7 +61,7 @@ public function askPermissions($backUrl, $redirectCb = NULL)
 		$this->storage->set('auth.state', $state);
 
 		$url = $this->authUrl . '?' . http_build_query($params);
-		if ($redirectCb === NULL) {
+		if ($redirectCb === null) {
 			header("Location: $url");
 			die();
 		} else {
@@ -75,13 +71,9 @@ public function askPermissions($backUrl, $redirectCb = NULL)
 
 
 	/**
-	 * @param  string
-	 * @param  string
-	 * @return Token
-	 *
 	 * @throws LoginException
 	 */
-	public function obtainToken($code, $state)
+	public function obtainToken(string $code, string $state): Token
 	{
 		if ($state !== $this->storage->get('auth.state')) {
 			throw new LoginException('OAuth security state does not match.');
@@ -122,45 +114,41 @@ public function obtainToken($code, $state)
 		}
 
 		$token = new Token($json->access_token, $json->token_type, strlen($json->scope) ? explode(',', $json->scope) : []);
-		$this->storage->set('auth.token', $token);
+		$this->storage->set('auth.token', $token->toArray());
 		$this->storage->remove('auth.state');
 
 		return $token;
 	}
 
 
-	/**
-	 * @return bool
-	 */
-	public function hasToken()
+	public function hasToken(): bool
 	{
-		return $this->storage->get('auth.token') !== NULL;
+		return $this->storage->get('auth.token') !== null;
 	}
 
 
 	/**
-	 * @return Token
-	 *
 	 * @throws Github\LogicException  when token has not been obtained yet
 	 */
-	public function getToken()
+	public function getToken(): Token
 	{
 		$token = $this->storage->get('auth.token');
-		if ($token === NULL) {
+		if ($token === null) {
 			throw new Github\LogicException('Token has not been obtained yet.');
+
+		} elseif ($token instanceof Token) {
+			/** @deprecated */
+			$token = $token->toArray();
+			$this->storage->set('auth.token', $token);
 		}
 
-		return $token;
+		return Token::createFromArray($token);
 	}
 
 
-	/**
-	 * @return self
-	 */
-	public function dropToken()
+	public function dropToken(): static
 	{
 		$this->storage->remove('auth.token');
 		return $this;
 	}
-
 }
diff --git a/src/Github/OAuth/Token.php b/src/Github/OAuth/Token.php
index e95a3e6..c1ad60e 100644
--- a/src/Github/OAuth/Token.php
+++ b/src/Github/OAuth/Token.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github\OAuth;
 
 use Milo\Github;
@@ -10,44 +12,28 @@
  *
  * @author  Miloslav Hůla (https://github.com/milo)
  */
-class Token extends Github\Sanity
+class Token
 {
-	/** @var string */
-	private $value;
-
-	/** @var string */
-	private $type;
-
-	/** @var string[] */
-	private $scopes;
+	use Github\Strict;
 
 
 	/**
-	 * @param  string
-	 * @param  string
-	 * @param  string[]
+	 * @param  string[] $scopes
 	 */
-	public function __construct($value, $type = '', array $scopes = [])
-	{
-		$this->value = $value;
-		$this->type = $type;
-		$this->scopes = $scopes;
-	}
+	public function __construct(
+		private string $value,
+		private string $type = '',
+		private array $scopes = []
+	) {}
 
 
-	/**
-	 * @return string
-	 */
-	public function getValue()
+	public function getValue(): string
 	{
 		return $this->value;
 	}
 
 
-	/**
-	 * @return string
-	 */
-	public function getType()
+	public function getType(): string
 	{
 		return $this->type;
 	}
@@ -56,7 +42,7 @@ public function getType()
 	/**
 	 * @return string[]
 	 */
-	public function getScopes()
+	public function getScopes(): array
 	{
 		return $this->scopes;
 	}
@@ -64,14 +50,11 @@ public function getScopes()
 
 	/**
 	 * @see https://developer.github.com/v3/oauth/#scopes
-	 *
-	 * @param  string
-	 * @return bool
 	 */
-	public function hasScope($scope)
+	public function hasScope(string $scope): bool
 	{
-		if (in_array($scope, $this->scopes, TRUE)) {
-			return TRUE;
+		if (in_array($scope, $this->scopes, true)) {
+			return true;
 		}
 
 		static $superiors = [
@@ -80,11 +63,28 @@ public function hasScope($scope)
 			'notifications' => 'repo',
 		];
 
-		if (array_key_exists($scope, $superiors) && in_array($superiors[$scope], $this->scopes, TRUE)) {
-			return TRUE;
+		if (array_key_exists($scope, $superiors) && in_array($superiors[$scope], $this->scopes, true)) {
+			return true;
 		}
 
-		return FALSE;
+		return false;
 	}
 
+
+	/** @internal */
+	public function toArray(): array
+	{
+		return [
+			'value' => $this->value,
+			'type' => $this->type,
+			'scopes' => $this->scopes,
+		];
+	}
+
+
+	/** @internal */
+	public static function createFromArray(array $data): static
+	{
+		return new static($data['value'], $data['type'], $data['scopes']);
+	}
 }
diff --git a/src/Github/Paginator.php b/src/Github/Paginator.php
index 8829d5f..70f461d 100644
--- a/src/Github/Paginator.php
+++ b/src/Github/Paginator.php
@@ -1,106 +1,82 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github;
 
 
 /**
- * Iterates through the Github API responses by Link: header.
+ * Iterates through the GitHub API responses by Link: header.
  *
  * @see https://developer.github.com/guides/traversing-with-pagination/
  *
  * @author  Miloslav Hůla (https://github.com/milo)
  */
-class Paginator extends Sanity implements \Iterator
+class Paginator implements \Iterator
 {
-	/** @var Api */
-	private $api;
+	use Strict;
 
-	/** @var Http\Request */
-	private $firstRequest;
+	private Http\Request $firstRequest;
 
-	/** @var Http\Request|NULL */
-	private $request;
+	private ?Http\Request $request;
 
-	/** @var Http\Response|NULL */
-	private $response;
+	private ?Http\Response $response;
 
-	/** @var int */
-	private $limit;
+	private ?int $limit = null;
 
-	/** @var int */
-	private $counter = 0;
+	private int $counter = 0;
 
 
-	public function __construct(Api $api, Http\Request $request)
-	{
-		$this->api = $api;
+	public function __construct(
+		private Api $api,
+		Http\Request $request
+	) {
 		$this->firstRequest = clone $request;
 	}
 
 
 	/**
 	 * Limits maximum steps of iteration.
-	 *
-	 * @param  int|NULL
-	 * @return self
 	 */
-	public function limit($limit)
+	public function limit(?int $limit): static
 	{
-		$this->limit = $limit === NULL
-			? NULL
-			: (int) $limit;
-
+		$this->limit = $limit;
 		return $this;
 	}
 
 
-	/**
-	 * @return void
-	 */
-	public function rewind()
+	public function rewind(): void
 	{
 		$this->request = $this->firstRequest;
-		$this->response = NULL;
+		$this->response = null;
 		$this->counter = 0;
 	}
 
 
-	/**
-	 * @return bool
-	 */
-	public function valid()
+	public function valid(): bool
 	{
-		return $this->request !== NULL && ($this->limit === NULL || $this->counter < $this->limit);
+		return $this->request !== null && ($this->limit === null || $this->counter < $this->limit);
 	}
 
 
-	/**
-	 * @return Http\Response
-	 */
-	public function current()
+	public function current(): Http\Response
 	{
 		$this->load();
 		return $this->response;
 	}
 
 
-	/**
-	 * @return int
-	 */
-	public function key()
+	public function key(): int
 	{
 		return static::parsePage($this->request->getUrl());
 	}
 
 
-	/**
-	 * @return void
-	 */
-	public function next()
+	public function next(): void
 	{
 		$this->load();
 
-		if ($url = static::parseLink($this->response->getHeader('Link'), 'next')) {
+		if ($url = static::parseLink((string) $this->response->getHeader('Link'), 'next')) {
 			$this->request = new Http\Request(
 				$this->request->getMethod(),
 				$url,
@@ -108,51 +84,38 @@ public function next()
 				$this->request->getContent()
 			);
 		} else {
-			$this->request = NULL;
+			$this->request = null;
 		}
 
-		$this->response = NULL;
+		$this->response = null;
 		$this->counter++;
 	}
 
 
-	private function load()
+	private function load(): void
 	{
-		if ($this->response === NULL) {
+		if ($this->response === null) {
 			$this->response = $this->api->request($this->request);
 		}
 	}
 
 
-	/**
-	 * @param  string
-	 * @return int
-	 */
-	public static function parsePage($url)
+	public static function parsePage(string $url): int
 	{
-		list (, $parametersStr) = explode('?', $url, 2) + ['', ''];
+		[, $parametersStr] = explode('?', $url, 2) + ['', ''];
 		parse_str($parametersStr, $parameters);
-
-		return isset($parameters['page'])
-			? max(1, (int) $parameters['page'])
-			: 1;
+		return max((int) ($parameters['page'] ?? 1), 1);
 	}
 
 
 	/**
 	 * @see  https://developer.github.com/guides/traversing-with-pagination/#navigating-through-the-pages
-	 *
-	 * @param  string
-	 * @param  string
-	 * @return string|NULL
 	 */
-	public static function parseLink($link, $rel)
+	public static function parseLink(string $link, string $rel): ?string
 	{
 		if (!preg_match('(<([^>]+)>;\s*rel="' . preg_quote($rel) . '")', $link, $match)) {
-			return NULL;
+			return null;
 		}
-
 		return $match[1];
 	}
-
 }
diff --git a/src/Github/Sanity.php b/src/Github/Sanity.php
deleted file mode 100644
index bb432f1..0000000
--- a/src/Github/Sanity.php
+++ /dev/null
@@ -1,28 +0,0 @@
-<?php
-
-namespace Milo\Github;
-
-
-/**
- * Undefined member access check. Stolen from Nette\Object (http://nette.org).
- */
-abstract class Sanity
-{
-	/**
-	 * @throws LogicException
-	 */
-	public function & __get($name)
-	{
-		throw new LogicException('Cannot read an undeclared property ' . get_class($this) . "::\$$name.");
-	}
-
-
-	/**
-	 * @throws LogicException
-	 */
-	public function __set($name, $value)
-	{
-		throw new LogicException('Cannot write to an undeclared property ' . get_class($this) . "::\$$name.");
-	}
-
-}
diff --git a/src/Github/Storages/FileCache.php b/src/Github/Storages/FileCache.php
index 52d75a3..a187936 100644
--- a/src/Github/Storages/FileCache.php
+++ b/src/Github/Storages/FileCache.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github\Storages;
 
 use Milo\Github;
@@ -10,18 +12,19 @@
  *
  * @author  Miloslav Hůla (https://github.com/milo)
  */
-class FileCache extends Github\Sanity implements ICache
+class FileCache implements ICache
 {
-	/** @var string */
-	private $dir;
+	use Github\Strict;
+
+	private string $dir;
 
 
 	/**
-	 * @param  string  temporary directory
+	 * @param  string $tempDir  temporary directory
 	 *
 	 * @throws MissingDirectoryException
 	 */
-	public function __construct($tempDir)
+	public function __construct(string $tempDir)
 	{
 		if (!is_dir($tempDir)) {
 			throw new MissingDirectoryException("Directory '$tempDir' is missing.");
@@ -30,7 +33,7 @@ public function __construct($tempDir)
 		$dir = $tempDir . DIRECTORY_SEPARATOR . 'milo.github-api';
 
 		if (!is_dir($dir)) {
-			set_error_handler(function($severity, $message, $file, $line) use ($dir, & $valid) {
+			set_error_handler(function($severity, $message, $file, $line) use ($dir, &$valid) {
 				restore_error_handler();
 				if (!is_dir($dir)) {
 					throw new MissingDirectoryException("Cannot create '$dir' directory.", 0, new \ErrorException($message, 0, $severity, $file, $line));
@@ -44,12 +47,8 @@ public function __construct($tempDir)
 	}
 
 
-	/**
-	 * @param  string
-	 * @param  mixed
-	 * @return mixed  stored value
-	 */
-	public function save($key, $value)
+	/** @inheritdoc */
+	public function save(string $key, mixed $value): mixed
 	{
 		file_put_contents(
 			$this->filePath($key),
@@ -61,11 +60,7 @@ public function save($key, $value)
 	}
 
 
-	/**
-	 * @param  string
-	 * @return mixed|NULL
-	 */
-	public function load($key)
+	public function load(string $key): mixed
 	{
 		$path = $this->filePath($key);
 		if (is_file($path) && ($fd = fopen($path, 'rb')) && flock($fd, LOCK_SH)) {
@@ -73,8 +68,8 @@ public function load($key)
 			flock($fd, LOCK_UN);
 			fclose($fd);
 
-			$success = TRUE;
-			set_error_handler(function() use (& $success) { return $success = FALSE; }, E_NOTICE);
+			$success = true;
+			set_error_handler(function() use (&$success) { return $success = false; }, E_NOTICE);
 			$cached = unserialize($cached);
 			restore_error_handler();
 
@@ -82,16 +77,13 @@ public function load($key)
 				return $cached;
 			}
 		}
+
+		return null;
 	}
 
 
-	/**
-	 * @param  string
-	 * @return string
-	 */
-	private function filePath($key)
+	private function filePath(string $key): string
 	{
 		return $this->dir . DIRECTORY_SEPARATOR . sha1($key) . '.php';
 	}
-
 }
diff --git a/src/Github/Storages/ICache.php b/src/Github/Storages/ICache.php
index 9540bbf..262b1cd 100644
--- a/src/Github/Storages/ICache.php
+++ b/src/Github/Storages/ICache.php
@@ -1,22 +1,17 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github\Storages;
 
 
 interface ICache
 {
 	/**
-	 * @param  string
-	 * @param  mixed
 	 * @return mixed  stored value
 	 */
-	function save($key, $value);
-
+	function save(string $key, mixed $value): mixed;
 
-	/**
-	 * @param  string
-	 * @return mixed|NULL
-	 */
-	function load($key);
 
+	function load(string $key): mixed;
 }
diff --git a/src/Github/Storages/ISessionStorage.php b/src/Github/Storages/ISessionStorage.php
index 169fa97..b857d47 100644
--- a/src/Github/Storages/ISessionStorage.php
+++ b/src/Github/Storages/ISessionStorage.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github\Storages;
 
 
@@ -8,25 +10,11 @@
  */
 interface ISessionStorage
 {
-	/**
-	 * @param  string
-	 * @param  mixed
-	 * @return self
-	 */
-	function set($name, $value);
-
+	function set(string $name, mixed $value): static;
 
-	/**
-	 * @param  string
-	 * @return mixed
-	 */
-	function get($name);
 
+	function get(string $name): mixed;
 
-	/**
-	 * @param  string
-	 * @return self
-	 */
-	function remove($name);
 
+	function remove(string $name): static;
 }
diff --git a/src/Github/Storages/SessionStorage.php b/src/Github/Storages/SessionStorage.php
index c2b1a91..77ccae2 100644
--- a/src/Github/Storages/SessionStorage.php
+++ b/src/Github/Storages/SessionStorage.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Milo\Github\Storages;
 
 use Milo\Github;
@@ -10,31 +12,21 @@
  *
  * @author  Miloslav Hůla (https://github.com/milo)
  */
-class SessionStorage extends Github\Sanity implements ISessionStorage
+class SessionStorage implements ISessionStorage
 {
-	const SESSION_KEY = 'milo.github-api';
+	use Github\Strict;
 
-	/** @var string */
-	private $sessionKey;
+	public const SESSION_KEY = 'milo.github-api';
 
 
-	/**
-	 * @param  string
-	 */
-	public function __construct($sessionKey = self::SESSION_KEY)
-	{
-		$this->sessionKey = $sessionKey;
-	}
+	public function __construct(
+		private string $sessionKey = self::SESSION_KEY
+	) {}
 
 
-	/**
-	 * @param  string
-	 * @param  mixed
-	 * @return self
-	 */
-	public function set($name, $value)
+	public function set(string $name, mixed $value): static
 	{
-		if ($value === NULL) {
+		if ($value === null) {
 			return $this->remove($name);
 		}
 
@@ -45,42 +37,25 @@ public function set($name, $value)
 	}
 
 
-	/**
-	 * @param  string
-	 * @return mixed
-	 */
-	public function get($name)
+	public function get(string $name): mixed
 	{
 		$this->check(__METHOD__);
-
-		return isset($_SESSION[$this->sessionKey][$name])
-			? $_SESSION[$this->sessionKey][$name]
-			: NULL;
+		return $_SESSION[$this->sessionKey][$name] ?? null;
 	}
 
 
-	/**
-	 * @param  string
-	 * @return self
-	 */
-	public function remove($name)
+	public function remove(string $name): static
 	{
 		$this->check(__METHOD__);
-
 		unset($_SESSION[$this->sessionKey][$name]);
-
 		return $this;
 	}
 
 
-	/**
-	 * @param  string
-	 */
-	private function check($method)
+	private function check(string $method): void
 	{
 		if (!isset($_SESSION)) {
 			trigger_error("Start session before using $method().", E_USER_WARNING);
 		}
 	}
-
 }
diff --git a/src/Github/Strict.php b/src/Github/Strict.php
new file mode 100644
index 0000000..3cfc578
--- /dev/null
+++ b/src/Github/Strict.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Milo\Github;
+
+
+/**
+ * Undefined member access check. Stolen from Nette (https://nette.org).
+ */
+trait Strict
+{
+	/** @throws LogicException */
+	public function &__get(string $name): mixed
+	{
+		throw new LogicException('Cannot read an undeclared property ' . get_class($this) . "::\$$name.");
+	}
+
+
+	/** @throws LogicException */
+	public function __set(string $name, mixed $value): void
+	{
+		throw new LogicException('Cannot write to an undeclared property ' . get_class($this) . "::\$$name.");
+	}
+}
diff --git a/src/Github/exceptions.php b/src/Github/exceptions.php
index 8b76b17..d54494e 100644
--- a/src/Github/exceptions.php
+++ b/src/Github/exceptions.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 
 /**
  * All Milo\Github exceptions at one place. Whole library does not throw anything else.
@@ -44,29 +46,20 @@ abstract class RuntimeException extends \RuntimeException implements IException
 	 */
 	abstract class ApiException extends RuntimeException
 	{
-		/** @var Http\Response|NULL */
-		private $response;
+		private ?Http\Response $response;
 
 
-		/**
-		 * @param string
-		 * @param int
-		 */
-		public function __construct($message = '', $code = 0, \Exception $previous = NULL, Http\Response $response = NULL)
+		public function __construct(string $message = '', int $code = 0, ?\Exception $previous = null, ?Http\Response $response = null)
 		{
 			parent::__construct($message, $code, $previous);
 			$this->response = clone $response;
 		}
 
 
-		/**
-		 * @return Http\Response|NULL
-		 */
-		final public function getResponse()
+		final public function getResponse(): ?Http\Response
 		{
 			return $this->response;
 		}
-
 	}
 
 
@@ -133,9 +126,7 @@ class InvalidResponseException extends ApiException
 	 * JSON cannot be decoded, or value cannot be encoded to JSON.
 	 */
 	class JsonException extends RuntimeException
-	{
-	}
-
+	{}
 }
 
 
@@ -148,7 +139,6 @@ class JsonException extends RuntimeException
 	 */
 	class BadResponseException extends Github\RuntimeException
 	{}
-
 }
 
 
@@ -160,7 +150,6 @@ class BadResponseException extends Github\RuntimeException
 	 */
 	class LoginException extends Github\RuntimeException
 	{}
-
 }
 
 
@@ -172,5 +161,4 @@ class LoginException extends Github\RuntimeException
 	 */
 	class MissingDirectoryException extends Github\RuntimeException
 	{}
-
 }
diff --git a/src/ca-chain.crt b/src/ca-chain.crt
index c95b005..9a0aa33 100644
--- a/src/ca-chain.crt
+++ b/src/ca-chain.crt
@@ -1,3 +1,58 @@
+#
+# DigiCert Global Root CA
+#
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
+
+#
+# DigiCert TLS Hybrid ECC SHA384 2020 CA1
+#
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
+
 #
 # DigiCert High Assurance EV Root CA
 #
diff --git a/src/github-api.php b/src/github-api.php
index 6524c5d..1d4195a 100644
--- a/src/github-api.php
+++ b/src/github-api.php
@@ -1,7 +1,9 @@
 <?php
 
+declare(strict_types=1);
+
 require __DIR__ . '/Github/exceptions.php';
-require __DIR__ . '/Github/Sanity.php';
+require __DIR__ . '/Github/Strict.php';
 require __DIR__ . '/Github/Helpers.php';
 
 require __DIR__ . '/Github/Storages/ICache.php';
diff --git a/tests/Github/Api.decode.phpt b/tests/Github/Api.decode.phpt
index 964ff44..350cdf3 100644
--- a/tests/Github/Api.decode.phpt
+++ b/tests/Github/Api.decode.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  */
@@ -22,10 +24,10 @@ Assert::same([], $api->decode($response));
 $e = Assert::exception(function() use ($api) {
 	$response = new Milo\Github\Http\Response(200, ['Content-Type' => 'application/json'], '[');
 	$api->decode($response);
-}, 'Milo\Github\InvalidResponseException', 'JSON decoding failed.');
+}, Milo\Github\InvalidResponseException::class, 'JSON decoding failed.');
 $e = Assert::exception(function() use ($e) {
 	throw $e->getPrevious();
-}, 'Milo\Github\JsonException');
+}, Milo\Github\JsonException::class);
 Assert::null($e->getPrevious());
 
 
@@ -33,63 +35,63 @@ Assert::null($e->getPrevious());
 $e = Assert::exception(function() use ($api) {
 	$response = new Milo\Github\Http\Response(200, ['Content-Type' => 'application/json'], '""');
 	$api->decode($response);
-}, 'Milo\Github\InvalidResponseException', 'Decoded JSON is not an array or object.');
+}, Milo\Github\InvalidResponseException::class, 'Decoded JSON is not an array or object.');
 Assert::null($e->getPrevious());
 
 
 $e = Assert::exception(function() use ($api) {
 	$response = new Milo\Github\Http\Response(400, ['Content-Type' => 'application/json'], '{"message":"error"}');
 	$api->decode($response);
-}, 'Milo\Github\BadRequestException', 'error', 400);
+}, Milo\Github\BadRequestException::class, 'error', 400);
 Assert::null($e->getPrevious());
 
 
 $e = Assert::exception(function() use ($api) {
 	$response = new Milo\Github\Http\Response(401, ['Content-Type' => 'application/json'], '{"message":"error"}');
 	$api->decode($response);
-}, 'Milo\Github\UnauthorizedException', 'error', 401);
+}, Milo\Github\UnauthorizedException::class, 'error', 401);
 Assert::null($e->getPrevious());
 
 
 $e = Assert::exception(function() use ($api) {
 	$response = new Milo\Github\Http\Response(403, ['Content-Type' => 'application/json'], '{"message":"error"}');
 	$api->decode($response);
-}, 'Milo\Github\ForbiddenException', 'error', 403);
+}, Milo\Github\ForbiddenException::class, 'error', 403);
 Assert::null($e->getPrevious());
 
 
 $e = Assert::exception(function() use ($api) {
 	$response = new Milo\Github\Http\Response(403, ['Content-Type' => 'application/json', 'X-RateLimit-Remaining' => '0'], '{"message":"error"}');
 	$api->decode($response);
-}, 'Milo\Github\RateLimitExceedException', 'error', 403);
+}, Milo\Github\RateLimitExceedException::class, 'error', 403);
 Assert::null($e->getPrevious());
 
 
 $e = Assert::exception(function() use ($api) {
 	$response = new Milo\Github\Http\Response(404, [], '');
 	$api->decode($response);
-}, 'Milo\Github\NotFoundException', 'Resource not found or not authorized to access.', 404);
+}, Milo\Github\NotFoundException::class, 'Resource not found or not authorized to access.', 404);
 Assert::null($e->getPrevious());
 
 
 $e = Assert::exception(function() use ($api) {
 	$response = new Milo\Github\Http\Response(422, ['Content-Type' => 'application/json'], '{"message":"error"}');
 	$api->decode($response);
-}, 'Milo\Github\UnprocessableEntityException', 'error', 422);
+}, Milo\Github\UnprocessableEntityException::class, 'error', 422);
 Assert::null($e->getPrevious());
 
 
 $e = Assert::exception(function() use ($api) {
 	$response = new Milo\Github\Http\Response(422, ['Content-Type' => 'application/json'], '{"message":"error", "errors":[{"a":"b","c":"d"}]}');
 	$api->decode($response);
-}, 'Milo\Github\UnprocessableEntityException', 'error[b:d]', 422);
+}, Milo\Github\UnprocessableEntityException::class, 'error[b:d]', 422);
 Assert::null($e->getPrevious());
 
 
 $e = Assert::exception(function() use ($api) {
 	$response = new Milo\Github\Http\Response(500, [], '');
 	$api->decode($response);
-}, 'Milo\Github\UnexpectedResponseException', 'Expected response with code < 300.', 500);
+}, Milo\Github\UnexpectedResponseException::class, 'Expected response with code < 300.', 500);
 Assert::null($e->getPrevious());
 
 
@@ -99,5 +101,5 @@ Assert::same('foo', $api->decode($response, [500]));
 $e = Assert::exception(function() use ($api) {
 	$response = new Milo\Github\Http\Response(200, [], '');
 	$api->decode($response, [201, 304]);
-}, 'Milo\Github\UnexpectedResponseException', 'Expected response with code 201 or 304.', 200);
+}, Milo\Github\UnexpectedResponseException::class, 'Expected response with code 201 or 304.', 200);
 Assert::null($e->getPrevious());
diff --git a/tests/Github/Api.expandColonParameters.phpt b/tests/Github/Api.expandColonParameters.phpt
index e691627..b24460f 100644
--- a/tests/Github/Api.expandColonParameters.phpt
+++ b/tests/Github/Api.expandColonParameters.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  */
@@ -7,9 +9,9 @@
 require __DIR__ . '/../bootstrap.php';
 
 
-class TestApi extends Milo\Github\Api
+class TestExpandColonApi extends Milo\Github\Api
 {
-	public function expandColonParameters($url, array $parameters, array $defaultParameters = [])
+	public function expandColonParameters(string $url, array $parameters, array $defaultParameters = []): string
 	{
 		return parent::expandColonParameters($url, $parameters, $defaultParameters);
 	}
@@ -18,7 +20,7 @@ class TestApi extends Milo\Github\Api
 
 # URL parameters like :name
 test(function() {
-	$api = new TestApi;
+	$api = new TestExpandColonApi;
 
 	$urls = [
 		'' => '?a=A&b=B',
@@ -28,6 +30,8 @@ test(function() {
 		':a/' => 'A?b=B',
 		'/:a/' => '/A?b=B',
 		'/:a/:b/c' => '/A/B/c',
+		'/:a.:b/c' => '/A.B/c',
+		'/:a...:b/c' => '/A...B/c',
 	];
 
 	foreach ($urls as $url => $expected) {
@@ -36,17 +40,17 @@ test(function() {
 
 	Assert::exception(function() use ($api) {
 		$api->expandColonParameters(':a', ['A' => 'a']);
-	}, 'Milo\Github\MissingParameterException', "Missing parameter 'a' for URL path ':a'.");
+	}, Milo\Github\MissingParameterException::class, "Missing parameter 'a' for URL path ':a'.");
 
 	Assert::exception(function() use ($api) {
 		$api->expandColonParameters(':a:b', ['a' => 'A', 'b' => 'B']);
-	}, 'Milo\Github\MissingParameterException', "Missing parameter 'a:b' for URL path ':a:b'.");
+	}, Milo\Github\MissingParameterException::class, "Missing parameter 'a:b' for URL path ':a:b'.");
 });
 
 
 # Parameters escaping
 test(function() {
-	$api = new TestApi;
+	$api = new TestExpandColonApi;
 
 	Assert::same('/with%20space', $api->expandColonParameters('/:name', ['name' => 'with space']));
 });
@@ -54,8 +58,16 @@ test(function() {
 
 # Default parameters expanding
 test(function() {
-	$api = new TestApi;
+	$api = new TestExpandColonApi;
 
 	Assert::same('/default', $api->expandColonParameters('/:var', [], ['var' => 'default']));
 	Assert::same('/set', $api->expandColonParameters('/:var', ['var' => 'set'], ['var' => 'default']));
 });
+
+
+# Expanding in absolute URL
+test(function () {
+	$api = new Milo\Github\Api;
+	$request = $api->createRequest('', 'https://host.:name.:tld/path/:name', ['name' => 'milo', 'tld' => 'cz']);
+	Assert::same('https://host.:name.:tld/path/milo?tld=cz', $request->getUrl());
+});
diff --git a/tests/Github/Api.expandUriTemplate.phpt b/tests/Github/Api.expandUriTemplate.phpt
index 7029ee2..2aa436f 100644
--- a/tests/Github/Api.expandUriTemplate.phpt
+++ b/tests/Github/Api.expandUriTemplate.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  */
@@ -7,15 +9,15 @@
 require __DIR__ . '/../bootstrap.php';
 
 
-class TestApi extends Milo\Github\Api
+class TestExpandUriTemplateApi extends Milo\Github\Api
 {
-	public function expandUriTemplate($url, array $parameters, array $defaultParameters = [])
+	public function expandUriTemplate(string $url, array $parameters, array $defaultParameters = []): string
 	{
 		return parent::expandUriTemplate($url, $parameters, $defaultParameters);
 	}
 }
 
-$api = new TestApi;
+$api = new TestExpandUriTemplateApi;
 
 # NULL (aka undefined)
 $cases = [
@@ -29,7 +31,7 @@ $cases = [
 	'&' => '',
 ];
 foreach ($cases as $operator => $expected) {
-	Assert::same($expected, $api->expandUriTemplate("{{$operator}a}", ['a' => NULL]));
+	Assert::same($expected, $api->expandUriTemplate("{{$operator}a}", ['a' => null]));
 }
 
 
@@ -46,7 +48,7 @@ $cases = [
 ];
 foreach ($cases as $operator => $expected) {
 	Assert::same($expected, $api->expandUriTemplate("{{$operator}a}", ['a' => '']));
-	Assert::same($expected, $api->expandUriTemplate("{{$operator}a}", ['a' => FALSE]));
+	Assert::same($expected, $api->expandUriTemplate("{{$operator}a}", ['a' => false]));
 }
 
 
@@ -328,7 +330,7 @@ test(function() use ($api) {
 		'y' => 768,
 		'empty' => '',
 		'empty_keys' => [],
-		'undef' => NULL,
+		'undef' => null,
 	];
 	$cases = [
 		# 3.2.1. Variable Expansion
@@ -469,3 +471,11 @@ test(function() use ($api) {
 		Assert::same($expected, $api->expandUriTemplate($template, $parameters));
 	}
 });
+
+
+# Expanding in absolute URL
+test(function () {
+	$api = new Milo\Github\Api;
+	$request = $api->createRequest('', 'https://host.{name}.{tld}/path/{name}', ['name' => 'milo', 'tld' => 'cz']);
+	Assert::same('https://host.{name}.{tld}/path/milo', $request->getUrl());
+});
diff --git a/tests/Github/Api.phpt b/tests/Github/Api.phpt
index c0f8d26..9280b7e 100644
--- a/tests/Github/Api.phpt
+++ b/tests/Github/Api.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  */
@@ -7,21 +9,30 @@
 require __DIR__ . '/../bootstrap.php';
 
 
-class MockIClient implements Milo\Github\Http\IClient
+class LogicExceptionMockClient implements Milo\Github\Http\IClient
 {
-	public function request(Milo\Github\Http\Request $request)
+	public function request(Milo\Github\Http\Request $request): Milo\Github\Http\Response
 	{
 		throw new \LogicException;
 	}
 
-	public function onRequest($cb) {}
-	public function onResponse($cb) {}
+
+	public function onRequest(?callable $callback): static
+	{
+		return $this;
+	}
+
+
+	public function onResponse(?callable $callback): static
+	{
+		return $this;
+	}
 }
 
 
 # Basics
 test(function() {
-	$client = new MockIClient;
+	$client = new LogicExceptionMockClient;
 	$api = new Milo\Github\Api($client);
 
 	Assert::same($client, $api->getClient());
@@ -29,18 +40,25 @@ test(function() {
 	Assert::same($api, $api->setUrl('url://test'));
 	Assert::same('url://test', $api->getUrl());
 
+	$clone = $api->withUrl('url://cloned');
+	Assert::notSame($api, $clone);
+	Assert::same('url://test', $api->getUrl());
+	Assert::same('url://cloned', $clone->getUrl());
+	Assert::same($api->getClient(), $clone->getClient());
+
 	$token = new Milo\Github\OAuth\Token('hash');
 	Assert::null($api->getToken());
 	Assert::same($api, $api->setToken($token));
 	Assert::same($token, $api->getToken());
-	$api->setToken(NULL);
+	$api->setToken(null);
 	Assert::null($api->getToken());
+
 });
 
 
 # createRequest()
 test(function() {
-	$client = new MockIClient;
+	$client = new LogicExceptionMockClient;
 	$api = new Milo\Github\Api($client);
 
 	# All slashes in URL
@@ -52,7 +70,7 @@ test(function() {
 
 	# No slashes in URL
 	$api->setUrl('url://test');
-	$request = $api->createRequest('', 'path', [], [], NULL);
+	$request = $api->createRequest('', 'path', [], [], null);
 	Assert::same('url://test/path', $request->getUrl());
 
 	# Array to JSON
@@ -60,7 +78,7 @@ test(function() {
 	Assert::same(['content-type' => 'application/json; charset=utf-8'], $request->getHeaders());
 	Assert::same('{"foo":"bar"}', $request->getContent());
 
-	## Object to JSON
+	# Object to JSON
 	$request = $api->createRequest('', '', [], [], (object) ['foo' => 'bar']);
 	Assert::same(['content-type' => 'application/json; charset=utf-8'], $request->getHeaders());
 	Assert::same('{"foo":"bar"}', $request->getContent());
@@ -69,48 +87,58 @@ test(function() {
 
 # Default parameters
 test(function() {
-	$client = new MockIClient;
+	$client = new LogicExceptionMockClient;
 	$api = new Milo\Github\Api($client);
 	$api->setUrl('url://test');
 
 	Assert::same([], $api->getDefaultParameters());
-	$request = $api->createRequest('', 'path', [], [], NULL);
+	$request = $api->createRequest('', 'path', [], [], null);
 	Assert::same('url://test/path', $request->getUrl());
 
 	$params = ['foo' => 'bar'];
 	$api->setDefaultParameters($params);
 
 	Assert::same($params, $api->getDefaultParameters());
-	$request = $api->createRequest('', 'path', [], [], NULL);
+	$request = $api->createRequest('', 'path', [], [], null);
 	Assert::same('url://test/path?foo=bar', $request->getUrl());
 
 	Assert::same($params, $api->getDefaultParameters());
-	$request = $api->createRequest('', 'path', ['foo' => 'fuzz'], [], NULL);
+	$request = $api->createRequest('', 'path', ['foo' => 'fuzz'], [], null);
 	Assert::same('url://test/path?foo=fuzz', $request->getUrl());
 });
 
 
-# Api called with full URL
+# Api called with absolute URL
 test(function() {
-	$client = new MockIClient;
+	$client = new LogicExceptionMockClient;
 	$api = new Milo\Github\Api($client);
 	$api->setUrl('url://test');
 
-	$request = $api->createRequest('', 'url://test/path', [], [], NULL);
+	$request = $api->createRequest('', 'url://test/path', [], [], null);
 	Assert::same('url://test/path', $request->getUrl());
 
-	$request = $api->createRequest('', 'url://tested/path', [], [], NULL);
+	$request = $api->createRequest('', 'url://tested/path', [], [], null);
 	Assert::same('url://test/ed/path', $request->getUrl());
 
-	$request = $api->createRequest('', 'uRl://TeSt/path', [], [], NULL);
+	$request = $api->createRequest('', 'uRl://TeSt/path', [], [], null);
 	Assert::same('url://test/path', $request->getUrl());
+
+	# Absolute HTTPS URL with different host
+	$request = $api->createRequest('', 'https://example.com', [], [], null);
+	Assert::same('https://example.com/', $request->getUrl());
+	$request = $api->createRequest('', 'https://example.com/path', [], [], null);
+	Assert::same('https://example.com/path', $request->getUrl());
+
+	# Absolute non-HTTPS URL with different host is not allowed (should be?)
+	$request = $api->createRequest('', 'http://example.com', [], [], null);
+	Assert::same('url://test/http://example.com', $request->getUrl());
 });
 
 
 # Paginator
 test(function() {
-	$client = new MockIClient;
+	$client = new LogicExceptionMockClient;
 	$api = new Milo\Github\Api($client);
 
-	Assert::type('Milo\Github\Paginator', $api->paginator(''));
+	Assert::type(Milo\Github\Paginator::class, $api->paginator(''));
 });
diff --git a/tests/Github/Api.request.phpt b/tests/Github/Api.request.phpt
index b1e28c8..8416c56 100644
--- a/tests/Github/Api.request.phpt
+++ b/tests/Github/Api.request.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  */
@@ -12,14 +14,23 @@ class MockIClient implements Milo\Github\Http\IClient
 	/** @var callable */
 	public $onRequest;
 
-	/** @return Milo\Github\Http\Response */
-	public function request(Milo\Github\Http\Request $request)
+
+	public function request(Milo\Github\Http\Request $request): Milo\Github\Http\Response
 	{
 		return call_user_func($this->onRequest, $request);
 	}
 
-	public function onRequest($cb) {}
-	public function onResponse($cb) {}
+
+	public function onRequest(?callable $callback): static
+	{
+		return $this;
+	}
+
+
+	public function onResponse(?callable $callback): static
+	{
+		return $this;
+	}
 }
 
 
@@ -35,6 +46,7 @@ $client->onRequest = function(Milo\Github\Http\Request $request) {
 	Assert::true($request->hasHeader('User-Agent'));
 	Assert::true($request->hasHeader('Foo'));
 	Assert::false($request->hasHeader('Authorization'));
+	return new Milo\Github\Http\Response(0, [], null);
 };
 $api->request($request);
 
@@ -44,14 +56,16 @@ $token = new Milo\Github\OAuth\Token('hash', 'type', []);
 $api->setToken($token);
 $client->onRequest = function(Milo\Github\Http\Request $request) {
 	Assert::true($request->hasHeader('Authorization'));
+	return new Milo\Github\Http\Response(0, [], null);
 };
 $api->request($request);
 
 
 # Without token again
-$api->setToken(NULL);
+$api->setToken(null);
 $client->onRequest = function(Milo\Github\Http\Request $request) {
 	Assert::false($request->hasHeader('Authorization'));
+	return new Milo\Github\Http\Response(0, [], null);
 };
 $api->request($request);
 
@@ -61,6 +75,7 @@ $client->onRequest = function(Milo\Github\Http\Request $request) {
 	Assert::same('DELETE', $request->getMethod());
 	Assert::same('https://api.github.com/url?a=b', $request->getUrl());
 	Assert::same('bar', $request->getHeader('Foo'));
+	return new Milo\Github\Http\Response(0, [], null);
 };
 $api->delete('/url', ['a' => 'b'], ['Foo' => 'bar']);
 
@@ -70,6 +85,7 @@ $client->onRequest = function(Milo\Github\Http\Request $request) {
 	Assert::same('GET', $request->getMethod());
 	Assert::same('https://api.github.com/url?a=b', $request->getUrl());
 	Assert::same('bar', $request->getHeader('Foo'));
+	return new Milo\Github\Http\Response(0, [], null);
 };
 $api->get('/url', ['a' => 'b'], ['Foo' => 'bar']);
 
@@ -79,6 +95,7 @@ $client->onRequest = function(Milo\Github\Http\Request $request) {
 	Assert::same('HEAD', $request->getMethod());
 	Assert::same('https://api.github.com/url?a=b', $request->getUrl());
 	Assert::same('bar', $request->getHeader('Foo'));
+	return new Milo\Github\Http\Response(0, [], null);
 };
 $api->head('/url', ['a' => 'b'], ['Foo' => 'bar']);
 
@@ -89,6 +106,7 @@ $client->onRequest = function(Milo\Github\Http\Request $request) {
 	Assert::same('https://api.github.com/url?a=b', $request->getUrl());
 	Assert::same('bar', $request->getHeader('Foo'));
 	Assert::same('{content}', $request->getContent());
+	return new Milo\Github\Http\Response(0, [], null);
 };
 $api->patch('/url', '{content}', ['a' => 'b'], ['Foo' => 'bar']);
 
@@ -99,6 +117,7 @@ $client->onRequest = function(Milo\Github\Http\Request $request) {
 	Assert::same('https://api.github.com/url?a=b', $request->getUrl());
 	Assert::same('bar', $request->getHeader('Foo'));
 	Assert::same('{content}', $request->getContent());
+	return new Milo\Github\Http\Response(0, [], null);
 };
 $api->post('/url', '{content}', ['a' => 'b'], ['Foo' => 'bar']);
 
@@ -109,6 +128,7 @@ $client->onRequest = function(Milo\Github\Http\Request $request) {
 	Assert::same('https://api.github.com/url?a=b', $request->getUrl());
 	Assert::same('bar', $request->getHeader('Foo'));
 	Assert::same('{content}', $request->getContent());
+	return new Milo\Github\Http\Response(0, [], null);
 };
 $api->put('/url', '{content}', ['a' => 'b'], ['Foo' => 'bar']);
 
diff --git a/tests/Github/Helpers.phpt b/tests/Github/Helpers.phpt
index 9941020..7375f48 100644
--- a/tests/Github/Helpers.phpt
+++ b/tests/Github/Helpers.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  */
@@ -8,16 +10,16 @@ require __DIR__ . '/../bootstrap.php';
 
 
 $client1 = Milo\Github\Helpers::createDefaultClient();
-Assert::type('Milo\Github\Http\IClient', $client1);
+Assert::type(Milo\Github\Http\IClient::class, $client1);
 
 $client2 = Milo\Github\Helpers::createDefaultClient();
-Assert::type('Milo\Github\Http\IClient', $client2);
+Assert::type(Milo\Github\Http\IClient::class, $client2);
 
 Assert::same($client1, $client2);
 
 
-$client3 = Milo\Github\Helpers::createDefaultClient(TRUE);
-Assert::type('Milo\Github\Http\IClient', $client3);
+$client3 = Milo\Github\Helpers::createDefaultClient(true);
+Assert::type(Milo\Github\Http\IClient::class, $client3);
 
 Assert::notSame($client1, $client3);
 Assert::notSame($client2, $client3);
diff --git a/tests/Github/Http/AbstractClient.phpt b/tests/Github/Http/AbstractClient.phpt
index ed57964..33d4e73 100644
--- a/tests/Github/Http/AbstractClient.phpt
+++ b/tests/Github/Http/AbstractClient.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  */
@@ -8,12 +10,12 @@
 require __DIR__ . '/../../bootstrap.php';
 
 
-class TestClient extends Milo\Github\Http\AbstractClient
+final class TestAbstractClient extends Milo\Github\Http\AbstractClient
 {
 	/** @var callable */
 	public $onProcess;
 
-	protected function process(Milo\Github\Http\Request $request)
+	protected function process(Milo\Github\Http\Request $request): Milo\Github\Http\Response
 	{
 		return call_user_func($this->onProcess, $request);
 	}
@@ -30,8 +32,8 @@ test(function() {
 		new Milo\Github\Http\Response(200, ['Location' => ''], ''),
 	];
 
-	$client = new TestClient;
-	$client->onProcess = function (Milo\Github\Http\Request $request) use (& $responses) {
+	$client = new TestAbstractClient;
+	$client->onProcess = function (Milo\Github\Http\Request $request) use (&$responses) {
 		return array_shift($responses);
 	};
 
@@ -54,16 +56,16 @@ test(function() {
 
 # onRequest(), onResponse()
 test(function() {
-	$client = new TestClient;
+	$client = new TestAbstractClient;
 	$client->onProcess = function() { return new Milo\Github\Http\Response(200, [], '{response}'); };
 
-	$onRequest = NULL;
-	$client->onRequest(function(Milo\Github\Http\Request $request) use (& $onRequest) {
+	$onRequest = null;
+	$client->onRequest(function(Milo\Github\Http\Request $request) use (&$onRequest) {
 		$onRequest = $request->getContent();
 	});
 
-	$onResponse = NULL;
-	$client->onResponse(function(Milo\Github\Http\Response $response) use (& $onResponse) {
+	$onResponse = null;
+	$client->onResponse(function(Milo\Github\Http\Response $response) use (&$onResponse) {
 		$onResponse = $response->getContent();
 	});
 
@@ -76,7 +78,7 @@ test(function() {
 
 # Additional headers
 test(function(){
-	$client = new TestClient;
+	$client = new TestAbstractClient;
 	$client->onProcess = function(Milo\Github\Http\Request $request) {
 		Assert::same([
 			'expect' => '',
diff --git a/tests/Github/Http/CachedClient.phpt b/tests/Github/Http/CachedClient.phpt
index bc6001b..37631cb 100644
--- a/tests/Github/Http/CachedClient.phpt
+++ b/tests/Github/Http/CachedClient.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  *
@@ -12,66 +14,62 @@ require __DIR__ . '/../../bootstrap.php';
 use Milo\Github\Http;
 
 
-class MockClient implements Http\IClient
+class MockClientCounter implements Http\IClient
 {
 	/** @var callable */
 	public $onRequest;
 
-	/** @var int */
-	public $requestCount = 0;
+	public int $requestCount = 0;
 
 
-	public function request(Http\Request $request)
+	public function request(Http\Request $request): Http\Response
 	{
 		$response = call_user_func($this->onRequest, $request);
 		$this->requestCount++;
 		return $response;
 	}
 
-	public function onRequest($foo)
+	public function onRequest(?callable $callback): static
 	{
-		trigger_error('Inner onRequest called: ' . var_export($foo, TRUE), E_USER_NOTICE);
+		trigger_error('Inner onRequest called: ' . var_export($callback, true), E_USER_NOTICE);
+		return $this;
 	}
 
-	public function onResponse($foo)
+	public function onResponse(?callable $callback): static
 	{
-		trigger_error('Inner onResponse called: ' . var_export($foo, TRUE), E_USER_NOTICE);
+		trigger_error('Inner onResponse called: ' . var_export($callback, true), E_USER_NOTICE);
+		return $this;
 	}
-
 }
 
 
 class MockCache implements Milo\Github\Storages\ICache
 {
-	private $cache = [];
+	private array $cache = [];
 
-	public function save($key, $value) {
+	public function save(string $key, mixed $value): mixed
+	{
 		return $this->cache[$key] = $value;
 	}
 
-	public function load($key)
+	public function load(string $key): mixed
 	{
-		return isset($this->cache[$key])
-			? $this->cache[$key]
-			: NULL;
+		return $this->cache[$key] ?? null;
 	}
-
 }
 
 
 class CachingTestCase extends Tester\TestCase
 {
-	/** @var Http\CachedClient */
-	private $client;
+	private Http\CachedClient $client;
 
-	/** @var MockClient */
-	private $innerClient;
+	private MockClientCounter $innerClient;
 
 
 	public function setup()
 	{
 		$cache = new MockCache;
-		$this->innerClient = new MockClient;
+		$this->innerClient = new MockClientCounter;
 		$this->client = new Http\CachedClient($cache, $this->innerClient);
 
 		$this->innerClient->onRequest = function (Http\Request $request) {
@@ -86,18 +84,20 @@ class CachingTestCase extends Tester\TestCase
 	{
 		Assert::same($this->innerClient, $this->client->getInnerClient());
 
-		Assert::error(function() {
-			Assert::same($this->client, $this->client->onRequest('callback-1'));
-			Assert::same($this->client, $this->client->onResponse('callback-2'));
+		$cb = fn() => null;
+
+		Assert::error(function() use ($cb) {
+			Assert::same($this->client, $this->client->onRequest($cb));
+			Assert::same($this->client, $this->client->onResponse($cb));
 		}, [
-			[E_USER_NOTICE, "Inner onRequest called: 'callback-1'"],
+			[E_USER_NOTICE, 'Inner onRequest called: %a?%Closure::%A%'],
 			[E_USER_NOTICE, 'Inner onResponse called: NULL'],
 		]);
 
-		$onResponseCalled = FALSE;
-		Assert::error(function() use (& $onResponseCalled) {
-			$this->client->onResponse(function() use (& $onResponseCalled) {
-				$onResponseCalled = TRUE;
+		$onResponseCalled = false;
+		Assert::error(function() use (&$onResponseCalled) {
+			$this->client->onResponse(function() use (&$onResponseCalled) {
+				$onResponseCalled = true;
 			});
 		}, E_USER_NOTICE, 'Inner onResponse called: NULL');
 
@@ -149,7 +149,7 @@ class CachingTestCase extends Tester\TestCase
 		};
 		$response = $this->client->request(new Http\Request('', '', [], '2'));
 		Assert::same('response-1', $response->getContent());
-		Assert::type('Milo\Github\Http\Response', $response->getPrevious());
+		Assert::type(Milo\Github\Http\Response::class, $response->getPrevious());
 		Assert::same(304, $response->getPrevious()->getCode());
 		Assert::same(2, $this->innerClient->requestCount);
 	}
@@ -178,7 +178,7 @@ class CachingTestCase extends Tester\TestCase
 
 		$response = $this->client->request(new Http\Request('', '', [], '2'));
 		Assert::same('response-1', $response->getContent());
-		Assert::type('Milo\Github\Http\Response', $response->getPrevious());
+		Assert::type(Milo\Github\Http\Response::class, $response->getPrevious());
 		Assert::same(304, $response->getPrevious()->getCode());
 		Assert::same(2, $this->innerClient->requestCount);
 	}
@@ -207,7 +207,7 @@ class CachingTestCase extends Tester\TestCase
 
 		$response = $this->client->request(new Http\Request('', '', [], '2'));
 		Assert::same('response-1', $response->getContent());
-		Assert::type('Milo\Github\Http\Response', $response->getPrevious());
+		Assert::type(Milo\Github\Http\Response::class, $response->getPrevious());
 		Assert::same(304, $response->getPrevious()->getCode());
 		Assert::same(2, $this->innerClient->requestCount);
 	}
@@ -226,14 +226,14 @@ class CachingTestCase extends Tester\TestCase
 		# From cache
 		$response = $this->client->request($request);
 		Assert::same('inner-200-same', $response->getContent());
-		Assert::type('Milo\Github\Http\Response', $response->getPrevious());
+		Assert::type(Milo\Github\Http\Response::class, $response->getPrevious());
 		Assert::same('inner-304-same', $response->getPrevious()->getContent());
 		Assert::same(2, $this->innerClient->requestCount);
 
 		# Again
 		$response = $this->client->request($request);
 		Assert::same('inner-200-same', $response->getContent());
-		Assert::type('Milo\Github\Http\Response', $response->getPrevious());
+		Assert::type(Milo\Github\Http\Response::class, $response->getPrevious());
 		Assert::same('inner-304-same', $response->getPrevious()->getContent());
 		Assert::same(3, $this->innerClient->requestCount);
 	}
@@ -250,13 +250,13 @@ class CachingTestCase extends Tester\TestCase
 
 		$response = $this->client->request($request);
 		Assert::same('inner-200-disabled', $response->getContent());
-		Assert::type('Milo\Github\Http\Response', $response->getPrevious());
+		Assert::type(Milo\Github\Http\Response::class, $response->getPrevious());
 		Assert::same('inner-304-disabled', $response->getPrevious()->getContent());
 		Assert::same(2, $this->innerClient->requestCount);
 
 		$response = $this->client->request($request);
 		Assert::same('inner-200-disabled', $response->getContent());
-		Assert::type('Milo\Github\Http\Response', $response->getPrevious());
+		Assert::type(Milo\Github\Http\Response::class, $response->getPrevious());
 		Assert::same('inner-304-disabled', $response->getPrevious()->getContent());
 		Assert::same(3, $this->innerClient->requestCount);
 	}
@@ -264,7 +264,7 @@ class CachingTestCase extends Tester\TestCase
 
 	public function testForbidRecheckEnabled()
 	{
-		$this->client = new Http\CachedClient(new MockCache, $this->innerClient, TRUE);
+		$this->client = new Http\CachedClient(new MockCache, $this->innerClient, true);
 
 		$request = new Http\Request('', '', [], 'enabled');
 
@@ -283,7 +283,6 @@ class CachingTestCase extends Tester\TestCase
 		Assert::null($response->getPrevious());
 		Assert::same(1, $this->innerClient->requestCount);
 	}
-
 }
 
 (new CachingTestCase)->run();
diff --git a/tests/Github/Http/Message.phpt b/tests/Github/Http/Message.phpt
index d606eb0..d754274 100644
--- a/tests/Github/Http/Message.phpt
+++ b/tests/Github/Http/Message.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  */
@@ -9,8 +11,15 @@ require __DIR__ . '/../../bootstrap.php';
 
 class TestMessage extends Milo\Github\Http\Message
 {
-	public function addHeader($name, $value) { return parent::addHeader($name, $value); }
-	public function setHeader($name, $value) { return parent::setHeader($name, $value); }
+	public function addHeader(string $name, ?string $value): static
+	{
+		return parent::addHeader($name, $value);
+	}
+
+	public function setHeader(string $name, ?string $value): static
+	{
+		return parent::setHeader($name, $value);
+	}
 }
 
 
@@ -42,10 +51,10 @@ Assert::same('val', $message->getHeader('Set'));
 Assert::same($message, $message->setHeader('a', 'val'));
 Assert::same('val', $message->getHeader('a'));
 
-Assert::same($message, $message->setHeader('a', NULL));
+Assert::same($message, $message->setHeader('a', null));
 Assert::false($message->hasHeader('a'));
 
 
 # Content
-Assert::same(NULL, (new TestMessage([], NULL))->getContent());
+Assert::same(null, (new TestMessage([], null))->getContent());
 Assert::same('', (new TestMessage([], ''))->getContent());
diff --git a/tests/Github/Http/Request.phpt b/tests/Github/Http/Request.phpt
index 8742c2e..73f6509 100644
--- a/tests/Github/Http/Request.phpt
+++ b/tests/Github/Http/Request.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  */
diff --git a/tests/Github/Http/Response.phpt b/tests/Github/Http/Response.phpt
index 9ffaa8e..9a51086 100644
--- a/tests/Github/Http/Response.phpt
+++ b/tests/Github/Http/Response.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  */
@@ -7,17 +9,16 @@
 require __DIR__ . '/../../bootstrap.php';
 
 
-$response = new Milo\Github\Http\Response('200', [], '');
+$response = new Milo\Github\Http\Response(200, [], '');
 
 Assert::same(200, $response->getCode());
 Assert::true($response->isCode(200));
-Assert::true($response->isCode('200'));
 Assert::false($response->isCode(0));
 
 
 # Previous
-$response = new Milo\Github\Http\Response('200', [], '1');
-$previous = new Milo\Github\Http\Response('200', [], '2');
+$response = new Milo\Github\Http\Response(200, [], '1');
+$previous = new Milo\Github\Http\Response(200, [], '2');
 Assert::null($response->getPrevious());
 
 $response->setPrevious($previous);
@@ -25,4 +26,4 @@ Assert::same($previous, $response->getPrevious());
 
 Assert::exception(function() use ($response, $previous) {
 	$response->setPrevious($previous);
-}, 'Milo\Github\LogicException', 'Previous response is already set.');
+}, Milo\Github\LogicException::class, 'Previous response is already set.');
diff --git a/tests/Github/Http/StreamClient.phpt b/tests/Github/Http/StreamClient.phpt
index 4e27a82..37e6307 100644
--- a/tests/Github/Http/StreamClient.phpt
+++ b/tests/Github/Http/StreamClient.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  */
@@ -8,21 +10,33 @@
 require __DIR__ . '/../../bootstrap.php';
 
 
-class TestClient extends Milo\Github\Http\StreamClient
+class TestStreamClient extends Milo\Github\Http\StreamClient
 {
 	/** @var callable */
 	public $onFileGetContents;
 
-	protected function fileGetContents($url, array $contextOptions)
+	protected function fileGetContents(string $url, array $contextOptions): array
 	{
 		return call_user_func($this->onFileGetContents, $url, $contextOptions);
 	}
+
+
+	public function onRequest(?callable $callback): static
+	{
+		return $this;
+	}
+
+
+	public function onResponse(?callable $callback): static
+	{
+		return $this;
+	}
 }
 
 
 # Common
 test(function() {
-	$client = new TestClient;
+	$client = new TestStreamClient;
 	$client->onFileGetContents = function($url, array $contextOptions) {
 		Assert::same('http://example.com', $url);
 		Assert::same([
@@ -31,13 +45,13 @@ test(function() {
 				'header' => "custom: header\r\nexpect: \r\nconnection: close\r\n",
 				'follow_location' => 0,
 				'protocol_version' => 1.1,
-				'ignore_errors' => TRUE,
+				'ignore_errors' => true,
 				'content' => '{content}',
 			],
 			'ssl' => [
-				'verify_peer' => TRUE,
+				'verify_peer' => true,
 				'cafile' => realpath(__DIR__ . '/../../../src/ca-chain.crt'),
-				'disable_compression' => TRUE,
+				'disable_compression' => true,
 			],
 		], $contextOptions);
 
@@ -54,14 +68,14 @@ test(function() {
 
 # SSL options
 test(function() {
-	$client = new TestClient(['option' => 'value']);
+	$client = new TestStreamClient(['option' => 'value']);
 	$client->onFileGetContents = function($url, array $contextOptions) {
 		Assert::type('array', $contextOptions['ssl']);
 		Assert::same([
 			'option' => 'value',
-			'verify_peer' => TRUE,
+			'verify_peer' => true,
 			'cafile' => realpath(__DIR__ . '/../../../src/ca-chain.crt'),
-			'disable_compression' => TRUE,
+			'disable_compression' => true,
 		], $contextOptions['ssl']);
 
 		return [200, [], ''];
diff --git a/tests/Github/OAuth/Configuration.phpt b/tests/Github/OAuth/Configuration.phpt
index 6e40d20..b3b14b6 100644
--- a/tests/Github/OAuth/Configuration.phpt
+++ b/tests/Github/OAuth/Configuration.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  */
diff --git a/tests/Github/OAuth/Login.askPermissions.default.phpt b/tests/Github/OAuth/Login.askPermissions.default.phpt
index 00e94a4..3c7b04b 100644
--- a/tests/Github/OAuth/Login.askPermissions.default.phpt
+++ b/tests/Github/OAuth/Login.askPermissions.default.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  *
@@ -7,7 +9,7 @@
  */
 
 require __DIR__ . '/../../bootstrap.php';
-Assert::true(TRUE);
+Assert::true(true);
 
 
 $_SESSION = [];
diff --git a/tests/Github/OAuth/Login.askPermissions.own.phpt b/tests/Github/OAuth/Login.askPermissions.own.phpt
index 356627b..719e37f 100644
--- a/tests/Github/OAuth/Login.askPermissions.own.phpt
+++ b/tests/Github/OAuth/Login.askPermissions.own.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  *
diff --git a/tests/Github/OAuth/Login.phpt b/tests/Github/OAuth/Login.phpt
index d8e6f9f..73ac823 100644
--- a/tests/Github/OAuth/Login.phpt
+++ b/tests/Github/OAuth/Login.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  *
@@ -14,30 +16,33 @@ class MockClient implements Milo\Github\Http\IClient
 	/** @var callable */
 	public $onRequest;
 
-	public function request(Milo\Github\Http\Request $request)
+	public function request(Milo\Github\Http\Request $request): Milo\Github\Http\Response
 	{
 		return call_user_func($this->onRequest, $request);
 	}
 
-	public function onRequest($cb) {}
-	public function onResponse($cb) {}
+
+	public function onRequest(?callable $callback): static
+	{
+		return $this;
+	}
+
+
+	public function onResponse(?callable $callback): static
+	{
+		return $this;
+	}
 }
 
 
 
 class LoginTestCase extends Tester\TestCase
 {
-	/** @var Milo\Github\OAuth\Configuration */
-	private $config;
-
-	/** @var Milo\Github\Storages\SessionStorage */
-	private $storage;
+	private Milo\Github\Storages\SessionStorage $storage;
 
-	/** @var MockClient */
-	private $client;
+	private MockClient $client;
 
-	/** @var Milo\Github\OAuth\Login */
-	private $login;
+	private Milo\Github\OAuth\Login $login;
 
 
 	public function setup()
@@ -58,7 +63,7 @@ class LoginTestCase extends Tester\TestCase
 		Assert::false($this->login->hasToken());
 		Assert::exception(function() {
 			$this->login->getToken();
-		}, 'Milo\Github\LogicException', 'Token has not been obtained yet.');
+		}, Milo\Github\LogicException::class, 'Token has not been obtained yet.');
 	}
 
 
@@ -81,7 +86,7 @@ class LoginTestCase extends Tester\TestCase
 		Assert::same(['a','b','c'], $token->getScopes());
 
 		Assert::true($this->login->hasToken());
-		Assert::type('Milo\Github\OAuth\Token', $this->login->getToken());
+		Assert::type(Milo\Github\OAuth\Token::class, $this->login->getToken());
 
 		Assert::same($this->login, $this->login->dropToken());
 		Assert::false($this->login->hasToken());
@@ -106,7 +111,7 @@ class LoginTestCase extends Tester\TestCase
 
 		Assert::exception(function() {
 			$this->login->obtainToken('', '');
-		}, 'Milo\Github\OAuth\LoginException', 'OAuth security state does not match.');
+		}, Milo\Github\OAuth\LoginException::class, 'OAuth security state does not match.');
 	}
 
 
@@ -119,10 +124,10 @@ class LoginTestCase extends Tester\TestCase
 		};
 		$e = Assert::exception(function() {
 			$this->login->obtainToken('', '*****');
-		}, 'Milo\Github\OAuth\LoginException', 'HTTP request failed.');
+		}, Milo\Github\OAuth\LoginException::class, 'HTTP request failed.');
 		$e = Assert::exception(function() use ($e) {
 			throw $e->getPrevious();
-		}, 'Milo\Github\Http\BadResponseException', 'fail');
+		}, Milo\Github\Http\BadResponseException::class, 'fail');
 		Assert::null($e->getPrevious());
 	}
 
@@ -136,10 +141,10 @@ class LoginTestCase extends Tester\TestCase
 		};
 		$e = Assert::exception(function() {
 			$this->login->obtainToken('', '*****');
-		}, 'Milo\Github\OAuth\LoginException', 'Bad JSON in response.');
+		}, Milo\Github\OAuth\LoginException::class, 'Bad JSON in response.');
 		$e = Assert::exception(function() use ($e) {
 			throw $e->getPrevious();
-		}, 'Milo\Github\JsonException', 'Syntax error, malformed JSON');
+		}, Milo\Github\JsonException::class, 'Syntax error');
 		Assert::null($e->getPrevious());
 	}
 
@@ -153,7 +158,7 @@ class LoginTestCase extends Tester\TestCase
 		};
 		$e = Assert::exception(function() {
 			$this->login->obtainToken('', '*****');
-		}, 'Milo\Github\OAuth\LoginException', 'fail');
+		}, Milo\Github\OAuth\LoginException::class, 'fail');
 		Assert::null($e->getPrevious());
 	}
 
@@ -166,10 +171,25 @@ class LoginTestCase extends Tester\TestCase
 		};
 		$e = Assert::exception(function() {
 			$this->login->obtainToken('', '*****');
-		}, 'Milo\Github\OAuth\LoginException', 'Unexpected response.');
+		}, Milo\Github\OAuth\LoginException::class, 'Unexpected response.');
 		Assert::null($e->getPrevious());
 	}
 
+
+	/** @deprecated */
+	public function testTokenObjectInSession()
+	{
+		$token = new Milo\Github\OAuth\Token('a', 'b', ['c', 'd']);
+		$this->storage->set('auth.token', $token);
+
+		Assert::type(Milo\Github\OAuth\Token::class, $this->login->getToken());
+		Assert::same([
+			'value' => 'a',
+			'type' => 'b',
+			'scopes' => ['c', 'd'],
+		], $this->storage->get('auth.token'));
+	}
+
 }
 
 (new LoginTestCase())->run();
diff --git a/tests/Github/OAuth/Token.phpt b/tests/Github/OAuth/Token.phpt
index dd5bead..85dda9c 100644
--- a/tests/Github/OAuth/Token.phpt
+++ b/tests/Github/OAuth/Token.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  */
@@ -23,3 +25,13 @@ Assert::true($token->hasScope('user'));
 Assert::true($token->hasScope('user:email'));
 Assert::false($token->hasScope('user:foo'));
 Assert::false($token->hasScope('foo'));
+
+$asArray = [
+	'value' => 'hash2',
+	'type' => 'type',
+	'scopes' => ['user'],
+];
+Assert::same($asArray, $token->toArray());
+
+$fromArray = Milo\Github\OAuth\Token::createFromArray($asArray);
+Assert::equal($token, $fromArray);
diff --git a/tests/Github/Paginator.phpt b/tests/Github/Paginator.phpt
index 1681e87..c9311cc 100644
--- a/tests/Github/Paginator.phpt
+++ b/tests/Github/Paginator.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  *
@@ -14,8 +16,7 @@ class MockApi extends Milo\Github\Api
 	/** @var callable */
 	public $onRequest;
 
-	/** @return Milo\Github\Http\Response */
-	public function request(Milo\Github\Http\Request $request)
+	public function request(Milo\Github\Http\Request $request): Milo\Github\Http\Response
 	{
 		return call_user_func($this->onRequest, $request);
 	}
@@ -24,8 +25,7 @@ class MockApi extends Milo\Github\Api
 
 class PaginatorTestCase extends Tester\TestCase
 {
-	/** @var MockApi */
-	private $api;
+	private MockApi $api;
 
 	public function setUp()
 	{
@@ -48,7 +48,7 @@ class PaginatorTestCase extends Tester\TestCase
 		));
 
 		$requests = [];
-		$this->api->onRequest = function(Milo\Github\Http\Request $request) use (& $requests, & $responses) {
+		$this->api->onRequest = function(Milo\Github\Http\Request $request) use (&$requests, &$responses) {
 			$requests[] = $request;
 			return array_shift($responses);
 		};
@@ -96,8 +96,8 @@ class PaginatorTestCase extends Tester\TestCase
 		Assert::same('url://b', Milo\Github\Paginator::parseLink($link, 'b'));
 		Assert::same('url://c', Milo\Github\Paginator::parseLink($link, 'c'));
 
-		Assert::same(NULL, Milo\Github\Paginator::parseLink('', ''));
-		Assert::same(NULL, Milo\Github\Paginator::parseLink('<url://test>; rel="foo"', 'bar'));
+		Assert::same(null, Milo\Github\Paginator::parseLink('', ''));
+		Assert::same(null, Milo\Github\Paginator::parseLink('<url://test>; rel="foo"', 'bar'));
 	}
 
 
@@ -114,7 +114,7 @@ class PaginatorTestCase extends Tester\TestCase
 			'url://test?page=20'
 		));
 
-		$this->api->onRequest = function(Milo\Github\Http\Request $request) use (& $requests, & $stack) {
+		$this->api->onRequest = function(Milo\Github\Http\Request $request) use (&$requests, &$stack) {
 			$requests[] = $request;
 			return array_shift($stack);
 		};
diff --git a/tests/Github/Sanity.phpt b/tests/Github/Sanity.phpt
deleted file mode 100644
index 239430b..0000000
--- a/tests/Github/Sanity.phpt
+++ /dev/null
@@ -1,20 +0,0 @@
-<?php
-
-/**
- * @author  Miloslav Hůla
- */
-
-require __DIR__ . '/../bootstrap.php';
-
-
-class TestSanity extends Milo\Github\Sanity
-{}
-
-Assert::exception(function() {
-	(new TestSanity)->undefined;
-}, 'Milo\Github\LogicException', 'Cannot read an undeclared property TestSanity::$undefined.');
-
-Assert::exception(function() {
-	$mock = new TestSanity;
-	$mock->undefined = '';
-}, 'Milo\Github\LogicException', 'Cannot write to an undeclared property TestSanity::$undefined.');
diff --git a/tests/Github/Storages/FileCache.phpt b/tests/Github/Storages/FileCache.phpt
index e97235f..0128df7 100644
--- a/tests/Github/Storages/FileCache.phpt
+++ b/tests/Github/Storages/FileCache.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  */
@@ -9,12 +11,12 @@ require __DIR__ . '/../../bootstrap.php';
 
 $e = Assert::exception(function() {
 	new Milo\Github\Storages\FileCache(__DIR__ . DIRECTORY_SEPARATOR . 'non-exists');
-}, 'Milo\Github\Storages\MissingDirectoryException', "Directory '%a%non-exists' is missing.");
+}, Milo\Github\Storages\MissingDirectoryException::class, "Directory '%a%non-exists' is missing.");
 
 Assert::null($e->getPrevious());
 
 
-define('TEMP_DIR', __DIR__ . '/temp.FileCache');
+const TEMP_DIR = __DIR__ . '/temp.FileCache';
 @mkdir(TEMP_DIR);  # @ = directory may exist
 Tester\Helpers::purge(TEMP_DIR);
 
@@ -22,13 +24,13 @@ $cache = new Milo\Github\Storages\FileCache(TEMP_DIR);
 
 Assert::null($cache->load('undefined'));
 
-$value = $cache->save('key-1', NULL);
+$value = $cache->save('key-1', null);
 Assert::null($cache->load('key-1'));
 
-$value = $cache->save('key-2', TRUE);
+$value = $cache->save('key-2', true);
 Assert::true($cache->load('key-2'));
 
-$value = $cache->save('key-3', FALSE);
+$value = $cache->save('key-3', false);
 Assert::false($cache->load('key-3'));
 
 $value = $cache->save('key-4', []);
diff --git a/tests/Github/Storages/SessionStorage.phpt b/tests/Github/Storages/SessionStorage.phpt
index 4906322..185658c 100644
--- a/tests/Github/Storages/SessionStorage.phpt
+++ b/tests/Github/Storages/SessionStorage.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  */
@@ -27,7 +29,7 @@ Assert::same([
 	'test' => ['foo' => $o],
 ],$_SESSION);
 
-Assert::same($storage, $storage->set('foo', NULL));
+Assert::same($storage, $storage->set('foo', null));
 Assert::same([
 	'test' => [],
 ], $_SESSION);
diff --git a/tests/Github/Strict.phpt b/tests/Github/Strict.phpt
new file mode 100644
index 0000000..fe51ba4
--- /dev/null
+++ b/tests/Github/Strict.phpt
@@ -0,0 +1,24 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @author  Miloslav Hůla
+ */
+
+require __DIR__ . '/../bootstrap.php';
+
+
+class TestStrict
+{
+	use Milo\Github\Strict;
+}
+
+Assert::exception(function() {
+	(new TestStrict)->undefined;
+}, Milo\Github\LogicException::class, 'Cannot read an undeclared property TestStrict::$undefined.');
+
+Assert::exception(function() {
+	$mock = new TestStrict;
+	$mock->undefined = '';
+}, Milo\Github\LogicException::class, 'Cannot write to an undeclared property TestStrict::$undefined.');
diff --git a/tests/Github/loader.phpt b/tests/Github/loader.phpt
index a89ff98..ca01d59 100644
--- a/tests/Github/loader.phpt
+++ b/tests/Github/loader.phpt
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @author  Miloslav Hůla
  *
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 7e17d95..c4682f5 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 if (!is_file($autoloadFile = __DIR__ . '/../vendor/autoload.php')) {
 	echo "Tester not found. Install Nette Tester using `composer update --dev`.\n";
 	exit(1);
@@ -14,6 +16,6 @@
 class Assert extends Tester\Assert
 {}
 
-function test(\closure $cb) {
+function test(\Closure $cb) {
 	$cb();
 }