diff --git a/psalm-baseline.xml b/psalm-baseline.xml
index 898b626..30d84c4 100644
--- a/psalm-baseline.xml
+++ b/psalm-baseline.xml
@@ -33,8 +33,8 @@
     </UndefinedClass>
   </file>
   <file src="test/AuthorizationMiddlewareFactoryTest.php">
-    <MissingClosureReturnType occurrences="1">
-      <code>function () {</code>
+    <MissingClosureReturnType occurrences="2">
+      <code>fn()</code>
     </MissingClosureReturnType>
     <MissingReturnType occurrences="2">
       <code>testFactory</code>
@@ -76,8 +76,8 @@
       <code>Argument::that([$this-&gt;request, 'reveal'])</code>
       <code>Argument::that([$this-&gt;request, 'reveal'])</code>
     </InvalidArgument>
-    <MissingClosureReturnType occurrences="1">
-      <code>function () {</code>
+    <MissingClosureReturnType occurrences="2">
+      <code>fn()</code>
     </MissingClosureReturnType>
     <MissingReturnType occurrences="4">
       <code>testConstructor</code>
diff --git a/src/AuthorizationMiddleware.php b/src/AuthorizationMiddleware.php
index b58551b..359633a 100644
--- a/src/AuthorizationMiddleware.php
+++ b/src/AuthorizationMiddleware.php
@@ -5,6 +5,7 @@
 namespace Mezzio\Authorization;
 
 use Mezzio\Authentication\UserInterface;
+use Mezzio\Authorization\AuthorizationInterface;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
 use Psr\Http\Server\MiddlewareInterface;
@@ -12,8 +13,7 @@
 
 class AuthorizationMiddleware implements MiddlewareInterface
 {
-    /** @var AuthorizationInterface */
-    private $authorization;
+    private AuthorizationInterface $authorization;
 
     /** @var callable */
     private $responseFactory;
@@ -23,9 +23,7 @@ public function __construct(AuthorizationInterface $authorization, callable $res
         $this->authorization = $authorization;
 
         // Ensures type safety of the composed factory
-        $this->responseFactory = function () use ($responseFactory): ResponseInterface {
-            return $responseFactory();
-        };
+        $this->responseFactory = static fn(): ResponseInterface => $responseFactory();
     }
 
     /**
diff --git a/test/AuthorizationMiddlewareFactoryTest.php b/test/AuthorizationMiddlewareFactoryTest.php
index 5be7220..1ac8782 100644
--- a/test/AuthorizationMiddlewareFactoryTest.php
+++ b/test/AuthorizationMiddlewareFactoryTest.php
@@ -23,8 +23,7 @@ class AuthorizationMiddlewareFactoryTest extends TestCase
     /** @var ContainerInterface|ObjectProphecy */
     private $container;
 
-    /** @var AuthorizationMiddlewareFactory */
-    private $factory;
+    private AuthorizationMiddlewareFactory $factory;
 
     /** @var AuthorizationInterface|ObjectProphecy */
     private $authorization;
@@ -41,9 +40,7 @@ protected function setUp(): void
         $this->factory           = new AuthorizationMiddlewareFactory();
         $this->authorization     = $this->prophesize(AuthorizationInterface::class);
         $this->responsePrototype = $this->prophesize(ResponseInterface::class);
-        $this->responseFactory   = function () {
-            return $this->responsePrototype->reveal();
-        };
+        $this->responseFactory   = fn() => $this->responsePrototype->reveal();
 
         $this->container
             ->get(AuthorizationInterface::class)
diff --git a/test/AuthorizationMiddlewareTest.php b/test/AuthorizationMiddlewareTest.php
index e89d3c3..9d67b61 100644
--- a/test/AuthorizationMiddlewareTest.php
+++ b/test/AuthorizationMiddlewareTest.php
@@ -41,9 +41,7 @@ protected function setUp(): void
         $this->request           = $this->prophesize(ServerRequestInterface::class);
         $this->handler           = $this->prophesize(RequestHandlerInterface::class);
         $this->responsePrototype = $this->prophesize(ResponseInterface::class);
-        $this->responseFactory   = function () {
-            return $this->responsePrototype->reveal();
-        };
+        $this->responseFactory   = fn() => $this->responsePrototype->reveal();
     }
 
     public function testConstructor()
diff --git a/test/ConfigProviderTest.php b/test/ConfigProviderTest.php
index dbbd0e7..91e8009 100644
--- a/test/ConfigProviderTest.php
+++ b/test/ConfigProviderTest.php
@@ -10,8 +10,7 @@
 
 class ConfigProviderTest extends TestCase
 {
-    /** @var ConfigProvider */
-    private $provider;
+    private ConfigProvider $provider;
 
     protected function setUp(): void
     {