diff --git a/classes/Config.php b/classes/Config.php
index 666b741..da7a10a 100644
--- a/classes/Config.php
+++ b/classes/Config.php
@@ -187,7 +187,7 @@ class Config
      *
      * @return string
      */
-    public static function addHttpToFormat(string $format)
+    public static function addHttpToFormat(string $format): string
     {
         $newFormat = [];
         foreach (explode('/', $format) as $subformat) {
@@ -266,7 +266,7 @@ class Config
      * @return Config
      * @throws ConfigException
      */
-    public static function fromFile(string $file)
+    public static function fromFile(string $file): Config
     {
         if (is_file($file)) {
             return new self(Yaml::parse(strval(file_get_contents($file))));
@@ -293,7 +293,7 @@ class Config
      *
      * @return Downloader
      */
-    public function getDownloader()
+    public function getDownloader(): Downloader
     {
         return new Downloader(
             $this->youtubedl,
@@ -308,7 +308,7 @@ class Config
     /**
      * @return string
      */
-    public function getAppVersion()
+    public function getAppVersion(): string
     {
         $version = PrettyVersions::getRootPackageVersion();
 
diff --git a/classes/Controller/BaseController.php b/classes/Controller/BaseController.php
index f57b0aa..f773bc1 100644
--- a/classes/Controller/BaseController.php
+++ b/classes/Controller/BaseController.php
@@ -111,7 +111,7 @@ abstract class BaseController
      *
      * @return string format
      */
-    protected function getFormat(Request $request)
+    protected function getFormat(Request $request): string
     {
         $format = $request->getQueryParam('format');
         if (!isset($format)) {
@@ -126,9 +126,9 @@ abstract class BaseController
      *
      * @param Request $request PSR-7 request
      *
-     * @return string Password
+     * @return string|null Password
      */
-    protected function getPassword(Request $request)
+    protected function getPassword(Request $request): ?string
     {
         $url = $request->getQueryParam('url');
 
@@ -151,7 +151,7 @@ abstract class BaseController
      *
      * @return Response HTTP response
      */
-    protected function displayError(Request $request, Response $response, string $message)
+    protected function displayError(Request $request, Response $response, string $message): Response
     {
         $controller = new FrontController($this->container);
 
diff --git a/classes/Controller/DownloadController.php b/classes/Controller/DownloadController.php
index b80890f..78e8b77 100644
--- a/classes/Controller/DownloadController.php
+++ b/classes/Controller/DownloadController.php
@@ -38,7 +38,7 @@ class DownloadController extends BaseController
      * @return Response HTTP response
      * @throws AlltubeLibraryException
      */
-    public function download(Request $request, Response $response)
+    public function download(Request $request, Response $response): Response
     {
         $url = $request->getQueryParam('url');
 
@@ -99,7 +99,7 @@ class DownloadController extends BaseController
      * @return Response HTTP response
      * @throws AlltubeLibraryException
      */
-    private function getConvertedAudioResponse(Request $request, Response $response)
+    private function getConvertedAudioResponse(Request $request, Response $response): Response
     {
         $from = null;
         $to = null;
@@ -135,7 +135,7 @@ class DownloadController extends BaseController
      * @throws PasswordException
      * @throws WrongPasswordException
      */
-    private function getAudioResponse(Request $request, Response $response)
+    private function getAudioResponse(Request $request, Response $response): Response
     {
         if (!empty($request->getQueryParam('from')) || !empty($request->getQueryParam('to'))) {
             // Force convert when we need to seek.
@@ -174,7 +174,7 @@ class DownloadController extends BaseController
      * @return Response HTTP response
      * @throws AlltubeLibraryException
      */
-    private function getStream(Request $request, Response $response)
+    private function getStream(Request $request, Response $response): Response
     {
         if (isset($this->video->entries)) {
             if ($this->config->convert && $request->getQueryParam('audio')) {
@@ -240,7 +240,7 @@ class DownloadController extends BaseController
      * @return Response HTTP response
      * @throws AlltubeLibraryException
      */
-    private function getRemuxStream(Request $request, Response $response)
+    private function getRemuxStream(Request $request, Response $response): Response
     {
         if (!$this->config->remux) {
             throw new RemuxException('You need to enable remux mode to merge two formats.');
@@ -267,7 +267,7 @@ class DownloadController extends BaseController
      * @return Response HTTP response
      * @throws AlltubeLibraryException
      */
-    private function getDownloadResponse(Request $request, Response $response)
+    private function getDownloadResponse(Request $request, Response $response): Response
     {
         try {
             $videoUrls = $this->video->getUrl();
@@ -306,7 +306,7 @@ class DownloadController extends BaseController
      * @throws YoutubedlException
      * @throws PopenStreamException
      */
-    private function getConvertedResponse(Request $request, Response $response)
+    private function getConvertedResponse(Request $request, Response $response): Response
     {
         $response = $response->withHeader(
             'Content-Disposition',
diff --git a/classes/Controller/FrontController.php b/classes/Controller/FrontController.php
index 38040b8..e091705 100644
--- a/classes/Controller/FrontController.php
+++ b/classes/Controller/FrontController.php
@@ -52,7 +52,7 @@ class FrontController extends BaseController
      *
      * @return Response HTTP response
      */
-    public function index(Request $request, Response $response)
+    public function index(Request $request, Response $response): Response
     {
         $this->view->render(
             $response,
@@ -78,7 +78,7 @@ class FrontController extends BaseController
      *
      * @return Response
      */
-    public function locale(Request $request, Response $response, array $data)
+    public function locale(Request $request, Response $response, array $data): Response
     {
         $this->localeManager->setLocale(new Locale($data['locale']));
 
@@ -94,7 +94,7 @@ class FrontController extends BaseController
      * @return Response HTTP response
      * @throws AlltubeLibraryException
      */
-    public function extractors(Request $request, Response $response)
+    public function extractors(Request $request, Response $response): Response
     {
         $this->view->render(
             $response,
@@ -119,7 +119,7 @@ class FrontController extends BaseController
      *
      * @return Response HTTP response
      */
-    public function password(Request $request, Response $response)
+    public function password(Request $request, Response $response): Response
     {
         $this->view->render(
             $response,
@@ -199,7 +199,7 @@ class FrontController extends BaseController
      * @return Response HTTP response
      * @throws AlltubeLibraryException
      */
-    public function info(Request $request, Response $response)
+    public function info(Request $request, Response $response): Response
     {
         $url = $request->getQueryParam('url') ?: $request->getQueryParam('v');
 
@@ -228,7 +228,7 @@ class FrontController extends BaseController
      *
      * @return Response HTTP response
      */
-    protected function displayError(Request $request, Response $response, string $message)
+    protected function displayError(Request $request, Response $response, string $message): Response
     {
         $this->view->render(
             $response,
@@ -248,7 +248,7 @@ class FrontController extends BaseController
      * @param Response $response
      * @return Response
      */
-    public function notFound(Request $request, Response $response)
+    public function notFound(Request $request, Response $response): Response
     {
         return $this->displayError($request, $response, $this->localeManager->t('Page not found'))
             ->withStatus(StatusCode::HTTP_NOT_FOUND);
@@ -259,7 +259,7 @@ class FrontController extends BaseController
      * @param Response $response
      * @return Response
      */
-    public function notAllowed(Request $request, Response $response)
+    public function notAllowed(Request $request, Response $response): Response
     {
         return $this->displayError($request, $response, $this->localeManager->t('Method not allowed'))
             ->withStatus(StatusCode::HTTP_METHOD_NOT_ALLOWED);
@@ -274,7 +274,7 @@ class FrontController extends BaseController
      *
      * @return Response HTTP response
      */
-    public function error(Request $request, Response $response, Throwable $error)
+    public function error(Request $request, Response $response, Throwable $error): Response
     {
         $this->logger->error($error);
 
diff --git a/classes/Controller/JsonController.php b/classes/Controller/JsonController.php
index 1247c6b..9f916bc 100644
--- a/classes/Controller/JsonController.php
+++ b/classes/Controller/JsonController.php
@@ -25,7 +25,7 @@ class JsonController extends BaseController
      * @return Response HTTP response
      * @throws AlltubeLibraryException
      */
-    public function json(Request $request, Response $response)
+    public function json(Request $request, Response $response): Response
     {
         $url = $request->getQueryParam('url');
 
diff --git a/classes/Factory/ConfigFactory.php b/classes/Factory/ConfigFactory.php
index 29cd0d7..c408b0e 100644
--- a/classes/Factory/ConfigFactory.php
+++ b/classes/Factory/ConfigFactory.php
@@ -20,7 +20,7 @@ class ConfigFactory
      * @return Config
      * @throws ConfigException
      */
-    public static function create(Container $container)
+    public static function create(Container $container): Config
     {
         $configPath = __DIR__ . '/../../config/config.yml';
         if (is_file($configPath)) {
diff --git a/classes/Factory/LocaleManagerFactory.php b/classes/Factory/LocaleManagerFactory.php
index 22fa261..30df471 100644
--- a/classes/Factory/LocaleManagerFactory.php
+++ b/classes/Factory/LocaleManagerFactory.php
@@ -15,10 +15,10 @@ class LocaleManagerFactory
 
     /**
      * @param Container $container
-     * @return LocaleManager|null
+     * @return LocaleManager
      * @throws DependencyException
      */
-    public static function create(Container $container)
+    public static function create(Container $container): LocaleManager
     {
         if (!class_exists('Locale')) {
             throw new DependencyException('You need to install the intl extension for PHP.');
diff --git a/classes/Factory/LoggerFactory.php b/classes/Factory/LoggerFactory.php
index 87cae0e..fe85133 100644
--- a/classes/Factory/LoggerFactory.php
+++ b/classes/Factory/LoggerFactory.php
@@ -18,7 +18,7 @@ class LoggerFactory
      * @param Container $container
      * @return Logger
      */
-    public static function create(Container $container)
+    public static function create(Container $container): Logger
     {
         $config = $container->get('config');
         if ($config->debug) {
diff --git a/classes/Factory/SessionFactory.php b/classes/Factory/SessionFactory.php
index b819b2f..05bb796 100644
--- a/classes/Factory/SessionFactory.php
+++ b/classes/Factory/SessionFactory.php
@@ -21,7 +21,7 @@ class SessionFactory
      * @param Container $container
      * @return Session
      */
-    public static function create(Container $container)
+    public static function create(Container $container): Session
     {
         $session_factory = new \Aura\Session\SessionFactory();
         $session = $session_factory->newInstance($_COOKIE);
diff --git a/classes/Factory/ViewFactory.php b/classes/Factory/ViewFactory.php
index d7048b7..1cc09e2 100644
--- a/classes/Factory/ViewFactory.php
+++ b/classes/Factory/ViewFactory.php
@@ -26,7 +26,7 @@ class ViewFactory
      *
      * @return string URL
      */
-    private static function getCanonicalUrl(Request $request)
+    private static function getCanonicalUrl(Request $request): string
     {
         /** @var Uri $uri */
         $uri = $request->getUri();
@@ -45,7 +45,7 @@ class ViewFactory
      * @return Smarty
      * @throws SmartyException
      */
-    public static function create(ContainerInterface $container, Request $request = null)
+    public static function create(ContainerInterface $container, Request $request = null): Smarty
     {
         if (!isset($request)) {
             $request = $container->get('request');
diff --git a/classes/Locale.php b/classes/Locale.php
index 9e81180..bacfc9d 100644
--- a/classes/Locale.php
+++ b/classes/Locale.php
@@ -48,7 +48,7 @@ class Locale
      *
      * @return string ISO 15897 code
      */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->getIso15897();
     }
@@ -58,7 +58,7 @@ class Locale
      *
      * @return string
      */
-    public function getFullName()
+    public function getFullName(): string
     {
         return PHPLocale::getDisplayName($this->getIso15897(), $this->getIso15897());
     }
@@ -68,7 +68,7 @@ class Locale
      *
      * @return string
      */
-    public function getIso15897()
+    public function getIso15897(): string
     {
         if (isset($this->region)) {
             return $this->language . '_' . $this->region;
@@ -82,7 +82,7 @@ class Locale
      *
      * @return string
      */
-    public function getBcp47()
+    public function getBcp47(): string
     {
         if (isset($this->region)) {
             return $this->language . '-' . $this->region;
@@ -96,7 +96,7 @@ class Locale
      *
      * @return string
      */
-    public function getIso3166()
+    public function getIso3166(): string
     {
         return strtolower($this->region);
     }
diff --git a/classes/LocaleManager.php b/classes/LocaleManager.php
index f3f7919..884579e 100644
--- a/classes/LocaleManager.php
+++ b/classes/LocaleManager.php
@@ -80,7 +80,7 @@ class LocaleManager
      *
      * @return Locale[]
      */
-    public function getSupportedLocales()
+    public function getSupportedLocales(): array
     {
         $return = [
             new Locale('en_US')
@@ -103,7 +103,7 @@ class LocaleManager
      *
      * @return Locale|null
      */
-    public function getLocale()
+    public function getLocale(): ?Locale
     {
         return $this->curLocale;
     }
@@ -140,7 +140,7 @@ class LocaleManager
      *
      * @return string Translated string
      */
-    public function smartyTranslate(array $params, string $text = null)
+    public function smartyTranslate(array $params, string $text = null): string
     {
         if (isset($params['params'])) {
             return $this->t($text, $params['params']);
@@ -157,7 +157,7 @@ class LocaleManager
      * @param mixed[] $params
      * @return string Translated string
      */
-    public function t(string $string = null, array $params = [])
+    public function t(string $string = null, array $params = []): string
     {
         if (isset($string)) {
             return $this->translator->trans($string, $params);
diff --git a/classes/Middleware/CspMiddleware.php b/classes/Middleware/CspMiddleware.php
index c3c72ff..3449df3 100644
--- a/classes/Middleware/CspMiddleware.php
+++ b/classes/Middleware/CspMiddleware.php
@@ -34,7 +34,7 @@ class CspMiddleware
      * @param Response $response
      * @return MessageInterface
      */
-    public function applyHeader(Response $response)
+    public function applyHeader(Response $response): MessageInterface
     {
         $csp = new CSPBuilder();
         $csp->addDirective('default-src', [])
diff --git a/classes/Middleware/LocaleMiddleware.php b/classes/Middleware/LocaleMiddleware.php
index b28f357..418ee7d 100644
--- a/classes/Middleware/LocaleMiddleware.php
+++ b/classes/Middleware/LocaleMiddleware.php
@@ -42,7 +42,7 @@ class LocaleMiddleware
      *
      * @return Locale|null Locale if chosen, nothing otherwise
      */
-    public function testLocale(array $proposedLocale)
+    public function testLocale(array $proposedLocale): ?Locale
     {
         foreach ($this->localeManager->getSupportedLocales() as $locale) {
             $parsedLocale = AcceptLanguage::parse($locale);
@@ -67,7 +67,7 @@ class LocaleMiddleware
      *
      * @return Response
      */
-    public function __invoke(Request $request, Response $response, callable $next)
+    public function __invoke(Request $request, Response $response, callable $next): Response
     {
         $headers = $request->getHeader('Accept-Language');
         $curLocale = $this->localeManager->getLocale();
diff --git a/classes/Stream/PlaylistArchiveStream.php b/classes/Stream/PlaylistArchiveStream.php
index 1bf08ff..065a57b 100644
--- a/classes/Stream/PlaylistArchiveStream.php
+++ b/classes/Stream/PlaylistArchiveStream.php
@@ -113,7 +113,7 @@ class PlaylistArchiveStream extends ZipArchive implements StreamInterface
      *
      * @return int|null
      */
-    public function getSize()
+    public function getSize(): ?int
     {
         return null;
     }
@@ -123,7 +123,7 @@ class PlaylistArchiveStream extends ZipArchive implements StreamInterface
      *
      * @return bool
      */
-    public function isSeekable()
+    public function isSeekable(): bool
     {
         return true;
     }
@@ -143,7 +143,7 @@ class PlaylistArchiveStream extends ZipArchive implements StreamInterface
      *
      * @return bool
      */
-    public function isWritable()
+    public function isWritable(): bool
     {
         return true;
     }
@@ -153,7 +153,7 @@ class PlaylistArchiveStream extends ZipArchive implements StreamInterface
      *
      * @return bool
      */
-    public function isReadable()
+    public function isReadable(): bool
     {
         return true;
     }
@@ -173,7 +173,7 @@ class PlaylistArchiveStream extends ZipArchive implements StreamInterface
      *
      * @param string|null $key string $key Specific metadata to retrieve.
      *
-     * @return array|mixed|null
+     * @return mixed|null
      */
     public function getMetadata($key = null)
     {
@@ -208,7 +208,7 @@ class PlaylistArchiveStream extends ZipArchive implements StreamInterface
      *
      * @return string
      */
-    public function __toString()
+    public function __toString(): string
     {
         $this->rewind();
 
@@ -243,7 +243,7 @@ class PlaylistArchiveStream extends ZipArchive implements StreamInterface
      *
      * @return bool
      */
-    public function eof()
+    public function eof(): bool
     {
         return $this->isComplete && feof($this->buffer);
     }
@@ -272,12 +272,12 @@ class PlaylistArchiveStream extends ZipArchive implements StreamInterface
     /**
      * Read data from the stream.
      *
-     * @param mixed $count Number of bytes to read
+     * @param mixed $length Number of bytes to read
      *
      * @return string|false
      * @throws AlltubeLibraryException
      */
-    public function read($count)
+    public function read($length)
     {
         // If the archive is complete, we only read the remaining buffer.
         if (!$this->isComplete) {
@@ -297,7 +297,7 @@ class PlaylistArchiveStream extends ZipArchive implements StreamInterface
                     }
                 } else {
                     // Continue streaming the current video.
-                    $this->stream_file_part($this->curVideoStream->read($count));
+                    $this->stream_file_part($this->curVideoStream->read($length));
                 }
             } else {
                 // Start streaming the first video.
@@ -305,7 +305,7 @@ class PlaylistArchiveStream extends ZipArchive implements StreamInterface
             }
         }
 
-        return fread($this->buffer, $count);
+        return fread($this->buffer, $length);
     }
 
     /**
diff --git a/classes/Stream/YoutubeChunkStream.php b/classes/Stream/YoutubeChunkStream.php
index bf64c0a..bb95138 100644
--- a/classes/Stream/YoutubeChunkStream.php
+++ b/classes/Stream/YoutubeChunkStream.php
@@ -39,7 +39,7 @@ class YoutubeChunkStream implements StreamInterface
      *
      * @return string
      */
-    public function read($length)
+    public function read($length): string
     {
         $size = intval($this->response->getHeader('Content-Length')[0]);
         if ($size - $this->tell() < $length) {
@@ -53,7 +53,7 @@ class YoutubeChunkStream implements StreamInterface
     /**
      * Reads all data from the stream into a string, from the beginning to end.
      */
-    public function __toString()
+    public function __toString(): string
     {
         return (string)$this->response->getBody();
     }
@@ -83,7 +83,7 @@ class YoutubeChunkStream implements StreamInterface
      *
      * @return int|null
      */
-    public function getSize()
+    public function getSize(): ?int
     {
         return $this->response->getBody()->getSize();
     }
@@ -93,7 +93,7 @@ class YoutubeChunkStream implements StreamInterface
      *
      * @return int
      */
-    public function tell()
+    public function tell(): int
     {
         return $this->response->getBody()->tell();
     }
@@ -103,7 +103,7 @@ class YoutubeChunkStream implements StreamInterface
      *
      * @return bool
      */
-    public function eof()
+    public function eof(): bool
     {
         return $this->response->getBody()->eof();
     }
@@ -113,7 +113,7 @@ class YoutubeChunkStream implements StreamInterface
      *
      * @return bool
      */
-    public function isSeekable()
+    public function isSeekable(): bool
     {
         return $this->response->getBody()->isSeekable();
     }
@@ -146,7 +146,7 @@ class YoutubeChunkStream implements StreamInterface
      *
      * @return bool
      */
-    public function isWritable()
+    public function isWritable(): bool
     {
         return $this->response->getBody()->isWritable();
     }
@@ -168,7 +168,7 @@ class YoutubeChunkStream implements StreamInterface
      *
      * @return bool
      */
-    public function isReadable()
+    public function isReadable(): bool
     {
         return $this->response->getBody()->isReadable();
     }
@@ -178,7 +178,7 @@ class YoutubeChunkStream implements StreamInterface
      *
      * @return string
      */
-    public function getContents()
+    public function getContents(): string
     {
         return $this->response->getBody()->getContents();
     }
@@ -188,7 +188,7 @@ class YoutubeChunkStream implements StreamInterface
      *
      * @param string|null $key Specific metadata to retrieve.
      *
-     * @return array|mixed|null
+     * @return mixed|null
      */
     public function getMetadata($key = null)
     {
diff --git a/classes/UglyRouter.php b/classes/UglyRouter.php
index 95a60cf..51f080f 100644
--- a/classes/UglyRouter.php
+++ b/classes/UglyRouter.php
@@ -26,7 +26,7 @@ class UglyRouter extends Router
      *
      * @link   https://github.com/nikic/FastRoute/blob/master/src/Dispatcher.php
      */
-    public function dispatch(ServerRequestInterface $request)
+    public function dispatch(ServerRequestInterface $request): array
     {
         $params = $request->getQueryParams();
         $uri = new Uri('', '');
@@ -53,7 +53,7 @@ class UglyRouter extends Router
      * @throws InvalidArgumentException If required data not provided
      * @throws RuntimeException         If named route does not exist
      */
-    public function pathFor($name, array $data = [], array $queryParams = [])
+    public function pathFor($name, array $data = [], array $queryParams = []): string
     {
         $queryParams['page'] = $name;
         $url = Uri::createFromString($this->relativePathFor($name, $data, $queryParams))->withPath('');
diff --git a/tests/BaseTest.php b/tests/BaseTest.php
index 7aa5351..3d41d6a 100644
--- a/tests/BaseTest.php
+++ b/tests/BaseTest.php
@@ -18,7 +18,7 @@ abstract class BaseTest extends TestCase
      *
      * @return string Path to file
      */
-    protected function getConfigFile()
+    protected function getConfigFile(): string
     {
         return __DIR__ . '/../config/config_test.yml';
     }
diff --git a/tests/ControllerTest.php b/tests/ControllerTest.php
index 6229ccf..40396bf 100644
--- a/tests/ControllerTest.php
+++ b/tests/ControllerTest.php
@@ -69,7 +69,7 @@ abstract class ControllerTest extends ContainerTest
      *
      * @return Response HTTP response
      */
-    protected function getRequestResult(string $request, array $params)
+    protected function getRequestResult(string $request, array $params): Response
     {
         return $this->controller->$request(
             $this->container->get('request')->withQueryParams($params),
diff --git a/tests/LocaleMiddlewareTest.php b/tests/LocaleMiddlewareTest.php
index b9a45cd..3452fdc 100644
--- a/tests/LocaleMiddlewareTest.php
+++ b/tests/LocaleMiddlewareTest.php
@@ -85,26 +85,32 @@ class LocaleMiddlewareTest extends ContainerTest
      * Check that the request contains an Accept-Language header.
      *
      * @param Request $request PSR-7 request
+     * @param Response $response
      *
-     * @return void
+     * @return Response
      */
-    public function assertHeader(Request $request)
+    public function assertHeader(Request $request, Response $response): Response
     {
         $header = $request->getHeader('Accept-Language');
         $this->assertEquals('foo-BAR', $header[0]);
+
+        return $response;
     }
 
     /**
      * Check that the request contains no Accept-Language header.
      *
      * @param Request $request PSR-7 request
+     * @param Response $response
      *
-     * @return void
+     * @return Response
      */
-    public function assertNoHeader(Request $request)
+    public function assertNoHeader(Request $request, Response $response): Response
     {
         $header = $request->getHeader('Accept-Language');
         $this->assertEmpty($header);
+
+        return $response;
     }
 
     /**
diff --git a/tests/VideoTest.php b/tests/VideoTest.php
index 6a26801..2107375 100644
--- a/tests/VideoTest.php
+++ b/tests/VideoTest.php
@@ -157,7 +157,7 @@ class VideoTest extends ContainerTest
      *
      * @return array[]
      */
-    public function urlProvider()
+    public function urlProvider(): array
     {
         return [
             [
@@ -193,7 +193,7 @@ class VideoTest extends ContainerTest
      *
      * @return array[]
      */
-    public function remuxUrlProvider()
+    public function remuxUrlProvider(): array
     {
         return [
             [
@@ -210,7 +210,7 @@ class VideoTest extends ContainerTest
      *
      * @return array[]
      */
-    public function m3uUrlProvider()
+    public function m3uUrlProvider(): array
     {
         return [
             [
@@ -227,7 +227,7 @@ class VideoTest extends ContainerTest
      *
      * @return array[]
      */
-    public function rtmpUrlProvider()
+    public function rtmpUrlProvider(): array
     {
         return [
             [
@@ -244,7 +244,7 @@ class VideoTest extends ContainerTest
      *
      * @return array[]
      */
-    public function errorUrlProvider()
+    public function errorUrlProvider(): array
     {
         return [
             ['http://example.com/video'],