diff --git a/.travis.yml b/.travis.yml
index 47134ff..07342d0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,10 +1,8 @@
 language: php
 php:
-    - '7.3'
-    - '7.4'
+    - '8.0'
 
 before_script:
-    - yes '' | pecl install yaml
     - composer install
 
 script:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index e616d5c..31608d2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,14 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 3.1.0 - 2021-04-03
+
+### Added
+- Support for PHP8
+
+### Changed
+- Support from `ulrack/services` to `grizz-it/services`.
+
 ## 3.0.1 - 2021-01-17
 
 ### Fixed
@@ -43,7 +51,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - The initial implementation of the package.
 
 # Versions
-- [3.0.1 > Unreleased](https://github.com/ulrack/web/compare/3.0.1...HEAD)
+- [3.1.0 > Unreleased](https://github.com/ulrack/web/compare/3.1.0...HEAD)
+- [3.0.1 > 3.1.0](https://github.com/ulrack/web/compare/3.0.1...3.1.0)
 - [3.0.0 > 3.0.1](https://github.com/ulrack/web/compare/3.0.0...3.0.1)
 - [2.0.0 > 3.0.0](https://github.com/ulrack/web/compare/2.0.0...3.0.0)
 - [1.0.1 > 2.0.0](https://github.com/ulrack/web/compare/1.0.1...2.0.0)
diff --git a/composer.json b/composer.json
index 3c4b4f4..93e65e1 100644
--- a/composer.json
+++ b/composer.json
@@ -11,13 +11,13 @@
     "prefer-stable": true,
     "minimum-stability": "stable",
     "require": {
-        "php": "^7.3",
-        "grizz-it/codec": "^1.0",
-        "grizz-it/configuration": "^1.1",
-        "grizz-it/enum": "^1.0",
-        "grizz-it/http": "^1.0",
-        "grizz-it/translator": "^1.1",
-        "ulrack/services": "^3.0"
+        "php": "^8.0",
+        "grizz-it/codec": "^1.1",
+        "grizz-it/configuration": "^1.3",
+        "grizz-it/enum": "^1.1",
+        "grizz-it/http": "^1.1",
+        "grizz-it/services": "^1.0",
+        "grizz-it/translator": "^1.2"
     },
     "authors": [
         {
@@ -55,7 +55,7 @@
         ]
     },
     "require-dev": {
-        "phpunit/phpunit": "^9.3",
+        "phpunit/phpunit": "^9.5",
         "squizlabs/php_codesniffer": "^3.5"
     }
 }
diff --git a/docs/usage/error.md b/docs/usage/error.md
index 0c310f1..1c6bf99 100644
--- a/docs/usage/error.md
+++ b/docs/usage/error.md
@@ -13,11 +13,13 @@ services. These are
 A definition for an error looks like the following:
 ```json
 {
-    "web.errors.default.api.400": {
-        "class": "\\Ulrack\\Web\\Component\\Error\\ConfigurableApiError",
-        "parameters": {
-            "errorStatusCode": 400,
-            "errorMessage": "Bad Request"
+    "services": {
+        "web.errors.default.api.400": {
+            "class": "\\Ulrack\\Web\\Component\\Error\\ConfigurableApiError",
+            "parameters": {
+                "errorStatusCode": 400,
+                "errorMessage": "Bad Request"
+            }
         }
     }
 }
diff --git a/src/Common/Endpoint/InputInterface.php b/src/Common/Endpoint/InputInterface.php
index bf1ec34..dbbff8b 100644
--- a/src/Common/Endpoint/InputInterface.php
+++ b/src/Common/Endpoint/InputInterface.php
@@ -34,7 +34,7 @@ public function hasParameter(string $key): bool;
      *
      * @return mixed
      */
-    public function getParameter(string $key);
+    public function getParameter(string $key): mixed;
 
     /**
      * Retrieves all parameters.
@@ -51,7 +51,7 @@ public function getParameters(): array;
      *
      * @return void
      */
-    public function setParameter(string $key, $value): void;
+    public function setParameter(string $key, mixed $value): void;
 
     /**
      * Retrieves a list of keys of available parameters.
diff --git a/src/Common/Endpoint/OutputInterface.php b/src/Common/Endpoint/OutputInterface.php
index 22e481b..5570806 100644
--- a/src/Common/Endpoint/OutputInterface.php
+++ b/src/Common/Endpoint/OutputInterface.php
@@ -14,7 +14,7 @@ interface OutputInterface
      *
      * @return mixed
      */
-    public function getOutput();
+    public function getOutput(): mixed;
 
     /**
      * Sets the value of the output.
@@ -23,7 +23,7 @@ public function getOutput();
      *
      * @return void
      */
-    public function setOutput($output): void;
+    public function setOutput(mixed $output): void;
 
     /**
      * Sets the serving protocol.
diff --git a/src/Component/Endpoint/Input.php b/src/Component/Endpoint/Input.php
index d965af9..00b20ae 100644
--- a/src/Component/Endpoint/Input.php
+++ b/src/Component/Endpoint/Input.php
@@ -17,14 +17,14 @@ class Input implements InputInterface
      *
      * @var RequestInterface
      */
-    private $request;
+    private RequestInterface $request;
 
     /**
      * Contains the parameters for the input.
      *
      * @var array
      */
-    private $parameters = [];
+    private array $parameters = [];
 
     /**
      * Constructor.
@@ -65,7 +65,7 @@ public function hasParameter(string $key): bool
      *
      * @return mixed
      */
-    public function getParameter(string $key)
+    public function getParameter(string $key): mixed
     {
         return $this->parameters[$key];
     }
@@ -88,7 +88,7 @@ public function getParameters(): array
      *
      * @return void
      */
-    public function setParameter(string $key, $value): void
+    public function setParameter(string $key, mixed $value): void
     {
         $this->parameters[$key] = $value;
     }
diff --git a/src/Component/Endpoint/Output.php b/src/Component/Endpoint/Output.php
index 55c482f..aa9eedf 100644
--- a/src/Component/Endpoint/Output.php
+++ b/src/Component/Endpoint/Output.php
@@ -16,49 +16,49 @@ class Output implements OutputInterface
      *
      * @var string
      */
-    private $protocol;
+    private string $protocol;
 
     /**
      * Contains the status code for the response.
      *
      * @var int
      */
-    private $statusCode = 200;
+    private int $statusCode = 200;
 
     /**
      * Contains the headers for the response.
      *
      * @var string[]
      */
-    private $headers = [];
+    private array $headers = [];
 
     /**
      * Contains the parameters.
      *
      * @var array
      */
-    private $parameters = [];
+    private array $parameters = [];
 
     /**
      * Contains the chosen content type.
      *
      * @var string
      */
-    private $contentType = '';
+    private string $contentType = '';
 
     /**
      * Contains the output of the response.
      *
      * @var mixed
      */
-    private $output;
+    private mixed $output;
 
     /**
      * Contains the accepted content types.
      *
      * @var string[]
      */
-    private $acceptedContentTypes;
+    private array $acceptedContentTypes;
 
     /**
      * Constructor.
@@ -78,7 +78,7 @@ public function __construct(string ...$acceptedContentTypes)
      *
      * @return mixed
      */
-    public function getOutput()
+    public function getOutput(): mixed
     {
         return $this->output;
     }
@@ -90,7 +90,7 @@ public function getOutput()
      *
      * @return void
      */
-    public function setOutput($output): void
+    public function setOutput(mixed $output): void
     {
         $this->output = $output;
     }
@@ -237,7 +237,7 @@ public function hasParameter(string $key): bool
      *
      * @return mixed
      */
-    public function getParameter(string $key)
+    public function getParameter(string $key): mixed
     {
         return $this->parameters[$key];
     }
@@ -250,7 +250,7 @@ public function getParameter(string $key)
      *
      * @return void
      */
-    public function setParameter(string $key, $value): void
+    public function setParameter(string $key, mixed $value): void
     {
         $this->parameters[$key] = $value;
     }
diff --git a/src/Component/Error/ConfigurableApiError.php b/src/Component/Error/ConfigurableApiError.php
index ec1fa40..67775df 100644
--- a/src/Component/Error/ConfigurableApiError.php
+++ b/src/Component/Error/ConfigurableApiError.php
@@ -19,35 +19,35 @@ class ConfigurableApiError implements ErrorInterface
      *
      * @var int
      */
-    private $errorStatusCode;
+    private int $errorStatusCode;
 
     /**
      * Contains the error code.
      *
-     * @var int
+     * @var int|null
      */
-    private $errorCode;
+    private ?int $errorCode;
 
     /**
      * Contains the error message.
      *
-     * @var string
+     * @var string|null
      */
-    private $errorMessage;
+    private ?string $errorMessage;
 
     /**
      * Contains the default content type.
      *
      * @var string
      */
-    private $defaultContentType;
+    private string $defaultContentType;
 
     /**
      * Constructor.
      *
      * @param int $errorStatusCode
-     * @param int $errorCode
-     * @param string $errorMessage
+     * @param int|null $errorCode
+     * @param string|null $errorMessage
      * @param string $defaultContentType
      */
     public function __construct(
diff --git a/src/Component/Error/ConfigurablePlainError.php b/src/Component/Error/ConfigurablePlainError.php
index b3d1c4a..778076c 100644
--- a/src/Component/Error/ConfigurablePlainError.php
+++ b/src/Component/Error/ConfigurablePlainError.php
@@ -19,29 +19,28 @@ class ConfigurablePlainError implements ErrorInterface
      *
      * @var int
      */
-    private $errorStatusCode;
+    private int $errorStatusCode;
 
     /**
      * Contains the error code.
      *
-     * @var int
+     * @var int|null
      */
-    private $errorCode;
+    private ?int $errorCode;
 
     /**
      * Contains the error message.
      *
-     * @var string
+     * @var string|null
      */
-    private $errorMessage;
+    private ?string $errorMessage;
 
     /**
      * Constructor.
      *
      * @param int $errorStatusCode
-     * @param int $errorCode
-     * @param string $errorMessage
-     * @param string $defaultContentType
+     * @param int|null $errorCode
+     * @param string|null $errorMessage
      */
     public function __construct(
         int $errorStatusCode,
diff --git a/src/Component/Error/ErrorHandler.php b/src/Component/Error/ErrorHandler.php
index 647fc38..9101ead 100644
--- a/src/Component/Error/ErrorHandler.php
+++ b/src/Component/Error/ErrorHandler.php
@@ -22,28 +22,28 @@ class ErrorHandler implements ErrorHandlerInterface
      *
      * @var InputInterface
      */
-    private $input;
+    private InputInterface $input;
 
     /**
      * Contains a reference to the output.
      *
      * @var OutputInterface
      */
-    private $output;
+    private OutputInterface $output;
 
     /**
      * Contains the output handler.
      *
      * @var OutputHandlerInterface
      */
-    private $outputHandler;
+    private OutputHandlerInterface $outputHandler;
 
     /**
      * Contains the error registry.
      *
      * @var ErrorRegistryInterface
      */
-    private $errorRegistry;
+    private ErrorRegistryInterface $errorRegistry;
 
     /**
      * Constructor.
diff --git a/src/Component/Error/ErrorRegistry.php b/src/Component/Error/ErrorRegistry.php
index 0773c04..42e6238 100644
--- a/src/Component/Error/ErrorRegistry.php
+++ b/src/Component/Error/ErrorRegistry.php
@@ -17,7 +17,7 @@ class ErrorRegistry implements ErrorRegistryInterface
      *
      * @var ErrorInterface[]
      */
-    private $errors;
+    private array $errors;
 
     /**
      * Constructor.
diff --git a/src/Component/Middleware/HostMatchingMiddleware.php b/src/Component/Middleware/HostMatchingMiddleware.php
index dfdc856..93b7324 100644
--- a/src/Component/Middleware/HostMatchingMiddleware.php
+++ b/src/Component/Middleware/HostMatchingMiddleware.php
@@ -18,7 +18,7 @@ class HostMatchingMiddleware implements MiddlewareInterface
      *
      * @var string[]
      */
-    private $hosts;
+    private array $hosts;
 
     /**
      * Constructor.
diff --git a/src/Component/Middleware/MethodMatchingMiddleware.php b/src/Component/Middleware/MethodMatchingMiddleware.php
index 1a26b15..e655302 100644
--- a/src/Component/Middleware/MethodMatchingMiddleware.php
+++ b/src/Component/Middleware/MethodMatchingMiddleware.php
@@ -18,7 +18,7 @@ class MethodMatchingMiddleware implements MiddlewareInterface
      *
      * @var string[]
      */
-    private $methods;
+    private array $methods;
 
     /**
      * Constructor.
diff --git a/src/Component/Middleware/MiddlewareAggregate.php b/src/Component/Middleware/MiddlewareAggregate.php
index eb87dd0..990a7cf 100644
--- a/src/Component/Middleware/MiddlewareAggregate.php
+++ b/src/Component/Middleware/MiddlewareAggregate.php
@@ -18,14 +18,14 @@ class MiddlewareAggregate implements MiddlewareInterface
      *
      * @var MiddlewareInterface[]
      */
-    private $middlewares;
+    private array $middlewares;
 
     /**
      * Contains the last error code.
      *
      * @var int
      */
-    private $lastErrorCode = 500;
+    private int $lastErrorCode = 500;
 
     /**
      * Constructor.
diff --git a/src/Component/Middleware/PathMatchingMiddleware.php b/src/Component/Middleware/PathMatchingMiddleware.php
index cc28c38..672a32e 100644
--- a/src/Component/Middleware/PathMatchingMiddleware.php
+++ b/src/Component/Middleware/PathMatchingMiddleware.php
@@ -18,7 +18,7 @@ class PathMatchingMiddleware implements MiddlewareInterface
      *
      * @var string
      */
-    private $route;
+    private string $route;
 
     /**
      * Constructor.
diff --git a/src/Component/Middleware/PortMatchingMiddleware.php b/src/Component/Middleware/PortMatchingMiddleware.php
index 6faf57f..1123b78 100644
--- a/src/Component/Middleware/PortMatchingMiddleware.php
+++ b/src/Component/Middleware/PortMatchingMiddleware.php
@@ -18,7 +18,7 @@ class PortMatchingMiddleware implements MiddlewareInterface
      *
      * @var int[]
      */
-    private $ports;
+    private array $ports;
 
     /**
      * Constructor.
diff --git a/src/Component/Output/CodecOutputConverter.php b/src/Component/Output/CodecOutputConverter.php
index ce99e7b..64db40a 100644
--- a/src/Component/Output/CodecOutputConverter.php
+++ b/src/Component/Output/CodecOutputConverter.php
@@ -20,14 +20,14 @@ class CodecOutputConverter implements OutputConverterInterface
      *
      * @var TranslatorInterface
      */
-    private $mimeToCodec;
+    private TranslatorInterface $mimeToCodec;
 
     /**
      * Contains the codec registry.
      *
      * @var CodecRegistryInterface
      */
-    private $codecRegistry;
+    private CodecRegistryInterface $codecRegistry;
 
     /**
      * Constructor.
diff --git a/src/Component/Output/OutputHandler.php b/src/Component/Output/OutputHandler.php
index e038ff1..7252e8c 100644
--- a/src/Component/Output/OutputHandler.php
+++ b/src/Component/Output/OutputHandler.php
@@ -21,14 +21,14 @@ class OutputHandler implements OutputHandlerInterface
      *
      * @var OutputConverterInterface[]
      */
-    private $outputConverters;
+    private array $outputConverters;
 
     /**
      * Contains the header handler.
      *
      * @var HeaderHandlerInterface
      */
-    private $headerHandler;
+    private HeaderHandlerInterface $headerHandler;
 
     /**
      * Constructor.
diff --git a/src/Component/Output/PlainOutputConverter.php b/src/Component/Output/PlainOutputConverter.php
index 4514056..de61535 100644
--- a/src/Component/Output/PlainOutputConverter.php
+++ b/src/Component/Output/PlainOutputConverter.php
@@ -17,7 +17,7 @@ class PlainOutputConverter implements OutputConverterInterface
      *
      * @var string[]
      */
-    private $contentTypes;
+    private array $contentTypes;
 
     /**
      * Constructor.
diff --git a/src/Component/Router/BaseRouter.php b/src/Component/Router/BaseRouter.php
index d434d21..85501c3 100644
--- a/src/Component/Router/BaseRouter.php
+++ b/src/Component/Router/BaseRouter.php
@@ -13,8 +13,8 @@
 use Ulrack\Web\Common\Endpoint\OutputInterface;
 use Ulrack\Web\Common\Endpoint\EndpointInterface;
 use Ulrack\Web\Common\Error\ErrorHandlerInterface;
-use Ulrack\Services\Common\ServiceFactoryInterface;
 use Ulrack\Web\Common\Output\OutputHandlerInterface;
+use GrizzIt\Services\Common\Factory\ServiceFactoryInterface;
 
 class BaseRouter implements RouterInterface
 {
@@ -23,35 +23,35 @@ class BaseRouter implements RouterInterface
      *
      * @var RouterInterface
      */
-    private $router;
+    private RouterInterface $router;
 
     /**
      * Determines whether a router has been found.
      *
      * @var bool
      */
-    private $found = false;
+    private bool $found = false;
 
     /**
      * Contains the output handler.
      *
      * @var OutputHandlerInterface
      */
-    private $outputHandler;
+    private OutputHandlerInterface $outputHandler;
 
     /**
      * Contains the error handler.
      *
      * @var ErrorHandlerInterface
      */
-    private $errorHandler;
+    private ErrorHandlerInterface $errorHandler;
 
     /**
      * Contains the service factory.
      *
      * @var ServiceFactoryInterface
      */
-    private $serviceFactory;
+    private ServiceFactoryInterface $serviceFactory;
 
     /**
      * Constructor.
diff --git a/src/Component/Router/MiddlewareRouter.php b/src/Component/Router/MiddlewareRouter.php
index 4f2b68c..89159df 100644
--- a/src/Component/Router/MiddlewareRouter.php
+++ b/src/Component/Router/MiddlewareRouter.php
@@ -20,21 +20,21 @@ class MiddlewareRouter implements RouterInterface
      *
      * @var RouterInterface
      */
-    private $router;
+    private RouterInterface $router;
 
     /**
      * Contains the middleware that takes care of the accepts method.
      *
      * @var MiddlewareInterface|null
      */
-    private $middlewareAccept;
+    private ?MiddlewareInterface $middlewareAccept;
 
     /**
      * Contains the middleware that takes care of the invoke method.
      *
      * @var MiddlewareInterface|null
      */
-    private $middlewareInvoke;
+    private ?MiddlewareInterface $middlewareInvoke;
 
     /**
      * Constructor.
diff --git a/src/Component/Router/RouterAggregate.php b/src/Component/Router/RouterAggregate.php
index 7f69c72..955e52a 100644
--- a/src/Component/Router/RouterAggregate.php
+++ b/src/Component/Router/RouterAggregate.php
@@ -19,14 +19,14 @@ class RouterAggregate implements RouterInterface
      *
      * @var RouterInterface[]
      */
-    private $routers;
+    private array $routers;
 
     /**
      * Contains the last accepted router.
      *
      * @var RouterInterface|null
      */
-    private $lastAccepted;
+    private ?RouterInterface $lastAccepted = null;
 
     /**
      * Constructor.
diff --git a/src/Exception/HttpException.php b/src/Exception/HttpException.php
index 09d2c93..b775ec5 100644
--- a/src/Exception/HttpException.php
+++ b/src/Exception/HttpException.php
@@ -17,7 +17,7 @@ class HttpException extends Exception
      *
      * @var int
      */
-    private $errorCode;
+    private int $errorCode;
 
     /**
      * Constructor.
diff --git a/src/Factory/InputFactory.php b/src/Factory/InputFactory.php
index 5b216b9..2233e51 100644
--- a/src/Factory/InputFactory.php
+++ b/src/Factory/InputFactory.php
@@ -26,28 +26,28 @@ class InputFactory
      *
      * @var TranslatorInterface
      */
-    private $mimeToCodec;
+    private TranslatorInterface $mimeToCodec;
 
     /**
      * Contains the codec registry.
      *
      * @var CodecRegistryInterface
      */
-    private $codecRegistry;
+    private CodecRegistryInterface $codecRegistry;
 
     /**
      * Contains the URI factory.
      *
      * @var UriFactory
      */
-    private $uriFactory;
+    private UriFactory $uriFactory;
 
     /**
      * Contains the identifier of the input stream.
      *
      * @var string
      */
-    private $inputStream;
+    private string $inputStream;
 
     /**
      * Constructor.
diff --git a/tests/Component/Router/BaseRouterTest.php b/tests/Component/Router/BaseRouterTest.php
index 7c2cdad..864f8e8 100644
--- a/tests/Component/Router/BaseRouterTest.php
+++ b/tests/Component/Router/BaseRouterTest.php
@@ -9,14 +9,14 @@
 
 use PHPUnit\Framework\TestCase;
 use Ulrack\Web\Component\Router\BaseRouter;
-use Ulrack\Web\Exception\UnauthorizedException;
 use Ulrack\Web\Common\Router\RouterInterface;
 use Ulrack\Web\Common\Endpoint\InputInterface;
 use Ulrack\Web\Common\Endpoint\OutputInterface;
+use Ulrack\Web\Exception\UnauthorizedException;
 use Ulrack\Web\Common\Endpoint\EndpointInterface;
 use Ulrack\Web\Common\Error\ErrorHandlerInterface;
-use Ulrack\Services\Common\ServiceFactoryInterface;
 use Ulrack\Web\Common\Output\OutputHandlerInterface;
+use GrizzIt\Services\Common\Factory\ServiceFactoryInterface;
 
 /**
  * @coversDefaultClass \Ulrack\Web\Component\Router\BaseRouter
diff --git a/tests/Factory/OutputFactoryTest.php b/tests/Factory/OutputFactoryTest.php
index 3022d7a..5a136a9 100644
--- a/tests/Factory/OutputFactoryTest.php
+++ b/tests/Factory/OutputFactoryTest.php
@@ -47,4 +47,29 @@ public function testCreate(): void
 
         $this->assertInstanceOf(OutputInterface::class, $subject->create($input));
     }
+
+    /**
+     * @covers ::create
+     * @covers ::parseAcceptHeader
+     *
+     * @return void
+     */
+    public function testCreateNoAccept(): void
+    {
+        $subject = new OutputFactory();
+
+        $input = $this->createMock(InputInterface::class);
+        $request = $this->createMock(RequestInterface::class);
+
+        $input->expects(static::once())
+            ->method('getRequest')
+            ->willReturn($request);
+
+        $request->expects(static::once())
+            ->method('hasHeader')
+            ->with('Accept')
+            ->willReturn(false);
+
+        $this->assertInstanceOf(OutputInterface::class, $subject->create($input));
+    }
 }