diff --git a/.php_cs.dist b/.php_cs.dist
index cb5d0a8..e50b9e9 100755
--- a/.php_cs.dist
+++ b/.php_cs.dist
@@ -36,7 +36,7 @@ $config = PhpCsFixer\Config::create()
         'php_unit_internal_class' => false,
         'php_unit_test_class_requires_covers' => false,
         'no_superfluous_phpdoc_tags' => true,
-        // 'static_lambda' => true,
+        'static_lambda' => true,
     ])
     ->setFinder($finder)
 ;
diff --git a/phpstan.neon b/phpstan.neon
index 4e57279..6a93043 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -8,6 +8,12 @@ parameters:
     ignoreErrors:
         # Symfony DI
         - '#Cannot call method scalarNode\(\) on Symfony\\Component\\Config\\Definition\\Builder\\NodeParentInterface\|null.#'
+        - "/Call to function method_exists.. with 'Symfony.+' and 'getRootNode' will always evaluate to false./"
 
         # Symfony Contracts
         - '#Method Symfony\\Contracts\\EventDispatcher\\EventDispatcherInterface::dispatch\(\) invoked with 2 parameters, 1 required.#'
+
+        # PHPUnit
+        -
+            message: '#Property .*::\$.* has no typehint specified.#'
+            path: tests/
diff --git a/src/Action/AuthErrorAction.php b/src/Action/AuthErrorAction.php
index 4c95085..4236fcf 100644
--- a/src/Action/AuthErrorAction.php
+++ b/src/Action/AuthErrorAction.php
@@ -74,7 +74,7 @@ public function __invoke(): Response
         $event = new AuthFailedEvent();
         $this->eventDispatcher->dispatch($event, Core23LastFmEvents::AUTH_ERROR);
 
-        if ($response = $event->getResponse()) {
+        if (null !== $response = $event->getResponse()) {
             return $response;
         }
 
diff --git a/src/Action/AuthSuccessAction.php b/src/Action/AuthSuccessAction.php
index 80dd7d5..1ba1e85 100644
--- a/src/Action/AuthSuccessAction.php
+++ b/src/Action/AuthSuccessAction.php
@@ -78,7 +78,7 @@ public function __invoke(): Response
         $event = new AuthSuccessEvent($session);
         $this->eventDispatcher->dispatch($event, Core23LastFmEvents::AUTH_SUCCESS);
 
-        if ($response = $event->getResponse()) {
+        if (null !== $response = $event->getResponse()) {
             return $response;
         }
 
diff --git a/src/Action/CheckAuthAction.php b/src/Action/CheckAuthAction.php
index ba8ef33..fc34792 100644
--- a/src/Action/CheckAuthAction.php
+++ b/src/Action/CheckAuthAction.php
@@ -44,9 +44,9 @@ public function __construct(RouterInterface $router, SessionManagerInterface $se
 
     public function __invoke(Request $request): RedirectResponse
     {
-        $token = $request->query->get('token');
+        $token = (string) $request->query->get('token', '');
 
-        if (!$token) {
+        if ('' === $token) {
             return new RedirectResponse($this->generateUrl('core23_lastfm_auth'));
         }
 
diff --git a/src/DependencyInjection/Configuration.php b/src/DependencyInjection/Configuration.php
index 33f61e1..af0ee89 100644
--- a/src/DependencyInjection/Configuration.php
+++ b/src/DependencyInjection/Configuration.php
@@ -22,7 +22,7 @@ public function getConfigTreeBuilder()
         $treeBuilder = new TreeBuilder('core23_lastfm');
 
         // Keep compatibility with symfony/config < 4.2
-        if (!method_exists($treeBuilder, 'getRootNode')) {
+        if (!method_exists(TreeBuilder::class, 'getRootNode')) {
             $rootNode = $treeBuilder->root('core23_lastfm');
         } else {
             $rootNode = $treeBuilder->getRootNode();
diff --git a/tests/Action/AuthErrorActionTest.php b/tests/Action/AuthErrorActionTest.php
index cb7fa3a..8768622 100644
--- a/tests/Action/AuthErrorActionTest.php
+++ b/tests/Action/AuthErrorActionTest.php
@@ -10,16 +10,13 @@
 namespace Core23\LastFmBundle\Tests\Action;
 
 use Core23\LastFmBundle\Action\AuthErrorAction;
-use Core23\LastFmBundle\Core23LastFmEvents;
-use Core23\LastFmBundle\Event\AuthFailedEvent;
 use Core23\LastFmBundle\Session\SessionManagerInterface;
+use Core23\LastFmBundle\Tests\EventDispatcher\TestEventDispatcher;
 use PHPUnit\Framework\TestCase;
-use Prophecy\Argument;
 use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
 use Symfony\Component\Routing\RouterInterface;
-use Symfony\Contracts\EventDispatcher\EventDispatcherInterface;
 use Twig\Environment;
 
 final class AuthErrorActionTest extends TestCase
@@ -37,7 +34,7 @@ protected function setUp(): void
         $this->twig            = $this->prophesize(Environment::class);
         $this->router          = $this->prophesize(RouterInterface::class);
         $this->sessionManager  = $this->prophesize(SessionManagerInterface::class);
-        $this->eventDispatcher = $this->prophesize(EventDispatcherInterface::class);
+        $this->eventDispatcher = new TestEventDispatcher();
     }
 
     public function testExecute(): void
@@ -50,15 +47,11 @@ public function testExecute(): void
             ->shouldBeCalled()
         ;
 
-        $this->eventDispatcher->dispatch(Argument::type(AuthFailedEvent::class), Core23LastFmEvents::AUTH_ERROR)
-            ->shouldBeCalled()
-        ;
-
         $action = new AuthErrorAction(
             $this->twig->reveal(),
             $this->router->reveal(),
             $this->sessionManager->reveal(),
-            $this->eventDispatcher->reveal()
+            $this->eventDispatcher
         );
 
         $response = $action();
@@ -79,17 +72,13 @@ public function testExecuteWithCaughtEvent(): void
 
         $eventResponse = new Response();
 
-        $this->eventDispatcher->dispatch(Argument::type(AuthFailedEvent::class), Core23LastFmEvents::AUTH_ERROR)
-            ->will(function ($args) use ($eventResponse) {
-                $args[0]->setResponse($eventResponse);
-            })
-        ;
+        $this->eventDispatcher->setResponse($eventResponse);
 
         $action = new AuthErrorAction(
             $this->twig->reveal(),
             $this->router->reveal(),
             $this->sessionManager->reveal(),
-            $this->eventDispatcher->reveal()
+            $this->eventDispatcher
         );
 
         $response = $action();
@@ -112,7 +101,7 @@ public function testExecuteWithNoAuth(): void
             $this->twig->reveal(),
             $this->router->reveal(),
             $this->sessionManager->reveal(),
-            $this->eventDispatcher->reveal()
+            $this->eventDispatcher
         );
 
         static::assertInstanceOf(RedirectResponse::class, $action());
diff --git a/tests/Action/AuthSuccessActionTest.php b/tests/Action/AuthSuccessActionTest.php
index 0162c3a..5b6fdba 100644
--- a/tests/Action/AuthSuccessActionTest.php
+++ b/tests/Action/AuthSuccessActionTest.php
@@ -11,16 +11,13 @@
 
 use Core23\LastFm\Session\SessionInterface;
 use Core23\LastFmBundle\Action\AuthSuccessAction;
-use Core23\LastFmBundle\Core23LastFmEvents;
-use Core23\LastFmBundle\Event\AuthSuccessEvent;
 use Core23\LastFmBundle\Session\SessionManagerInterface;
+use Core23\LastFmBundle\Tests\EventDispatcher\TestEventDispatcher;
 use PHPUnit\Framework\TestCase;
-use Prophecy\Argument;
 use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
 use Symfony\Component\Routing\RouterInterface;
-use Symfony\Contracts\EventDispatcher\EventDispatcherInterface;
 use Twig\Environment;
 
 final class AuthSuccessActionTest extends TestCase
@@ -38,7 +35,7 @@ protected function setUp(): void
         $this->twig            = $this->prophesize(Environment::class);
         $this->router          = $this->prophesize(RouterInterface::class);
         $this->sessionManager  = $this->prophesize(SessionManagerInterface::class);
-        $this->eventDispatcher = $this->prophesize(EventDispatcherInterface::class);
+        $this->eventDispatcher = new TestEventDispatcher();
     }
 
     public function testExecute(): void
@@ -55,10 +52,6 @@ public function testExecute(): void
             ->willReturn('FooUser')
         ;
 
-        $this->eventDispatcher->dispatch(Argument::type(AuthSuccessEvent::class), Core23LastFmEvents::AUTH_SUCCESS)
-            ->shouldBeCalled()
-        ;
-
         $this->twig->render('@Core23LastFm/Auth/success.html.twig', [
             'name' => 'FooUser',
         ])->shouldBeCalled();
@@ -67,7 +60,7 @@ public function testExecute(): void
             $this->twig->reveal(),
             $this->router->reveal(),
             $this->sessionManager->reveal(),
-            $this->eventDispatcher->reveal()
+            $this->eventDispatcher
         );
 
         $response = $action();
@@ -92,17 +85,13 @@ public function testExecuteWithCaughtEvent(): void
 
         $eventResponse = new Response();
 
-        $this->eventDispatcher->dispatch(Argument::type(AuthSuccessEvent::class), Core23LastFmEvents::AUTH_SUCCESS)
-            ->will(function ($args) use ($eventResponse) {
-                $args[0]->setResponse($eventResponse);
-            })
-        ;
+        $this->eventDispatcher->setResponse($eventResponse);
 
         $action = new AuthSuccessAction(
             $this->twig->reveal(),
             $this->router->reveal(),
             $this->sessionManager->reveal(),
-            $this->eventDispatcher->reveal()
+            $this->eventDispatcher
         );
 
         $response = $action();
@@ -125,7 +114,7 @@ public function testExecuteNoAuth(): void
             $this->twig->reveal(),
             $this->router->reveal(),
             $this->sessionManager->reveal(),
-            $this->eventDispatcher->reveal()
+            $this->eventDispatcher
         );
 
         static::assertInstanceOf(RedirectResponse::class, $action());
@@ -149,7 +138,7 @@ public function testExecuteNoSession(): void
             $this->twig->reveal(),
             $this->router->reveal(),
             $this->sessionManager->reveal(),
-            $this->eventDispatcher->reveal()
+            $this->eventDispatcher
         );
 
         static::assertInstanceOf(RedirectResponse::class, $action());
diff --git a/tests/Core23LastFmBundleTest.php b/tests/Core23LastFmBundleTest.php
index dd42025..4318d4b 100644
--- a/tests/Core23LastFmBundleTest.php
+++ b/tests/Core23LastFmBundleTest.php
@@ -12,17 +12,9 @@
 use Core23\LastFmBundle\Core23LastFmBundle;
 use Core23\LastFmBundle\DependencyInjection\Core23LastFmExtension;
 use PHPUnit\Framework\TestCase;
-use Symfony\Component\HttpKernel\Bundle\BundleInterface;
 
 final class Core23LastFmBundleTest extends TestCase
 {
-    public function testItIsInstantiable(): void
-    {
-        $bundle = new Core23LastFmBundle();
-
-        static::assertInstanceOf(BundleInterface::class, $bundle);
-    }
-
     public function testGetContainerExtension(): void
     {
         $bundle = new Core23LastFmBundle();
diff --git a/tests/Event/AuthFailedEventTest.php b/tests/Event/AuthFailedEventTest.php
index c057b7a..824ec30 100644
--- a/tests/Event/AuthFailedEventTest.php
+++ b/tests/Event/AuthFailedEventTest.php
@@ -12,17 +12,9 @@
 use Core23\LastFmBundle\Event\AuthFailedEvent;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\HttpFoundation\Response;
-use Symfony\Contracts\EventDispatcher\Event;
 
 final class AuthFailedEventTest extends TestCase
 {
-    public function testCreation(): void
-    {
-        $event = new AuthFailedEvent();
-
-        static::assertInstanceOf(Event::class, $event);
-    }
-
     public function testGetResponse(): void
     {
         $event = new AuthFailedEvent();
diff --git a/tests/Event/AuthSuccessEventTest.php b/tests/Event/AuthSuccessEventTest.php
index e00e3ed..69c709f 100644
--- a/tests/Event/AuthSuccessEventTest.php
+++ b/tests/Event/AuthSuccessEventTest.php
@@ -13,19 +13,9 @@
 use Core23\LastFmBundle\Event\AuthSuccessEvent;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\HttpFoundation\Response;
-use Symfony\Contracts\EventDispatcher\Event;
 
 final class AuthSuccessEventTest extends TestCase
 {
-    public function testCreation(): void
-    {
-        $session = $this->prophesize(SessionInterface::class);
-
-        $event = new AuthSuccessEvent($session->reveal());
-
-        static::assertInstanceOf(Event::class, $event);
-    }
-
     public function testGetUsername(): void
     {
         $session = $this->prophesize(SessionInterface::class);
diff --git a/tests/EventDispatcher/TestEventDispatcher.php b/tests/EventDispatcher/TestEventDispatcher.php
new file mode 100644
index 0000000..0228fa0
--- /dev/null
+++ b/tests/EventDispatcher/TestEventDispatcher.php
@@ -0,0 +1,32 @@
+<?php
+
+/*
+ * (c) Christian Gripp <mail@core23.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Core23\LastFmBundle\Tests\EventDispatcher;
+
+use Core23\LastFmBundle\Event\AuthFailedEvent;
+use Core23\LastFmBundle\Event\AuthSuccessEvent;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Contracts\EventDispatcher\EventDispatcherInterface;
+
+final class TestEventDispatcher implements EventDispatcherInterface
+{
+    private $response;
+
+    public function dispatch($event)
+    {
+        if ($event instanceof AuthFailedEvent || $event instanceof AuthSuccessEvent) {
+            $event->setResponse($this->response);
+        }
+    }
+
+    public function setResponse(Response $response): void
+    {
+        $this->response = $response;
+    }
+}
diff --git a/tests/Session/SessionManagerTest.php b/tests/Session/SessionManagerTest.php
index ed7494a..ec2e33f 100644
--- a/tests/Session/SessionManagerTest.php
+++ b/tests/Session/SessionManagerTest.php
@@ -10,7 +10,6 @@
 namespace Core23\LastFmBundle\Tests\Session;
 
 use Core23\LastFm\Session\Session as LastFmSession;
-use Core23\LastFm\Session\SessionInterface;
 use Core23\LastFmBundle\Session\SessionManager;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\HttpFoundation\Session\Session;
@@ -71,8 +70,6 @@ public function testStore(): void
 
         $manager = new SessionManager($session->reveal());
         $manager->store($lastfmSession);
-
-        static::assertTrue(true);
     }
 
     public function testClear(): void
@@ -97,7 +94,6 @@ public function testGetSession(): void
 
         $manager = new SessionManager($session->reveal());
 
-        /** @var SessionInterface $lastfmSession */
         $lastfmSession = $manager->getSession();
 
         static::assertNotNull($lastfmSession);
diff --git a/vendor-bin/phpstan/composer.json b/vendor-bin/phpstan/composer.json
index d247e05..e13413d 100644
--- a/vendor-bin/phpstan/composer.json
+++ b/vendor-bin/phpstan/composer.json
@@ -1,9 +1,12 @@
 {
     "require": {
+        "ekino/phpstan-banned-code": "^0.1",
         "jangregor/phpstan-prophecy": "^0.4",
         "phpstan/extension-installer": "^1.0",
         "phpstan/phpstan": "^0.11",
-        "phpstan/phpstan-phpunit": "^0.11"
+        "phpstan/phpstan-phpunit": "^0.11",
+        "phpstan/phpstan-strict-rules": "^0.11",
+        "phpstan/phpstan-symfony": "^0.11"
     },
     "conflict": {
         "phpunit/phpunit": ">=8.0"