diff --git a/core-bundle/src/Controller/InitializeController.php b/core-bundle/src/Controller/InitializeController.php
index 9cb15d1d1b9..bfb5f077ca4 100644
--- a/core-bundle/src/Controller/InitializeController.php
+++ b/core-bundle/src/Controller/InitializeController.php
@@ -127,12 +127,12 @@ private function handleException(\Throwable $e, Request $request, $type): void
 
         try {
             $event = new ResponseEvent($this->get('http_kernel'), $request, $type, $response);
-            $this->get('event_dispatcher')->dispatch(KernelEvents::RESPONSE, $event);
+            $this->get('event_dispatcher')->dispatch($event, KernelEvents::RESPONSE);
             $response = $event->getResponse();
 
             $this->get('event_dispatcher')->dispatch(
-                KernelEvents::FINISH_REQUEST,
-                new FinishRequestEvent($this->get('http_kernel'), $request, $type)
+                new FinishRequestEvent($this->get('http_kernel'), $request, $type),
+                KernelEvents::FINISH_REQUEST
             );
 
             $this->get('request_stack')->pop();
diff --git a/core-bundle/src/Exception/ServiceUnavailableException.php b/core-bundle/src/Exception/ServiceUnavailableException.php
index 262273c1c8b..bde82237f05 100644
--- a/core-bundle/src/Exception/ServiceUnavailableException.php
+++ b/core-bundle/src/Exception/ServiceUnavailableException.php
@@ -12,7 +12,7 @@
 
 namespace Contao\CoreBundle\Exception;
 
-@trigger_error('Using the "ServiceUnavailableException" class has been deprecated and will no longer work in Contao 5.0. Use the "Lexik\Bundle\MaintenanceBundle\Exception\ServiceUnavailableException" class instead.', E_USER_DEPRECATED);
+@trigger_error('Using the "Contao\CoreBundle\Exception\ServiceUnavailableException" class has been deprecated and will no longer work in Contao 5.0. Use the "Lexik\Bundle\MaintenanceBundle\Exception\ServiceUnavailableException" class instead.', E_USER_DEPRECATED);
 
 /**
  * @deprecated Deprecated since Contao 4.1, to be removed in Contao 5.0; use the
diff --git a/core-bundle/tests/DependencyInjection/Compiler/AddAssetsPackagesPassTest.php b/core-bundle/tests/DependencyInjection/Compiler/AddAssetsPackagesPassTest.php
index 70ffce306e3..ac29d72200a 100644
--- a/core-bundle/tests/DependencyInjection/Compiler/AddAssetsPackagesPassTest.php
+++ b/core-bundle/tests/DependencyInjection/Compiler/AddAssetsPackagesPassTest.php
@@ -143,6 +143,7 @@ public function testUsesTheJsonManifestVersionStrategyForBundles(): void
         $this->assertSame('assets._version_manifest_json', (string) $service->getArgument(1));
         $this->assertTrue($container->hasDefinition('assets._version_manifest_json'));
 
+        /** @var ChildDefinition $definition */
         $definition = $container->getDefinition('assets._version_manifest_json');
 
         $this->assertInstanceOf(ChildDefinition::class, $definition);
diff --git a/core-bundle/tests/Migration/MigrationCollectionTest.php b/core-bundle/tests/Migration/MigrationCollectionTest.php
index 83013123175..ce5631f47a1 100644
--- a/core-bundle/tests/Migration/MigrationCollectionTest.php
+++ b/core-bundle/tests/Migration/MigrationCollectionTest.php
@@ -24,7 +24,7 @@ public function testGetPendingNames(): void
         $migrations = new MigrationCollection($this->getMigrationServices());
         $pendingMigrations = $migrations->getPendingNames();
 
-        if (!\is_array($pendingMigrations)) {
+        if ($pendingMigrations instanceof \Traversable) {
             $pendingMigrations = iterator_to_array($pendingMigrations);
         }
 
@@ -36,7 +36,7 @@ public function testRunMigrations(): void
         $migrations = new MigrationCollection($this->getMigrationServices());
         $results = $migrations->run();
 
-        if (!\is_array($results)) {
+        if ($results instanceof \Traversable) {
             $results = iterator_to_array($results);
         }
 
diff --git a/installation-bundle/src/Database/AbstractVersionUpdate.php b/installation-bundle/src/Database/AbstractVersionUpdate.php
index 0092a28d1c4..aac15568ee2 100644
--- a/installation-bundle/src/Database/AbstractVersionUpdate.php
+++ b/installation-bundle/src/Database/AbstractVersionUpdate.php
@@ -12,12 +12,11 @@
 
 namespace Contao\InstallationBundle\Database;
 
-use Contao\CoreBundle\Migration\AbstractMigration;
 use Doctrine\DBAL\Connection;
 use Symfony\Component\DependencyInjection\ContainerAwareInterface;
 use Symfony\Component\DependencyInjection\ContainerAwareTrait;
 
-@trigger_error(sprintf('Using the "%s" class has been deprecated and will no longer work in Contao 5.0. Use the "%s" class instead.', AbstractVersionUpdate::class, AbstractMigration::class), E_USER_DEPRECATED);
+@trigger_error('Using the "Contao\InstallationBundle\Database\AbstractVersionUpdate" class has been deprecated and will no longer work in Contao 5.0. Use the "Contao\CoreBundle\Migration\AbstractMigration" class instead.', E_USER_DEPRECATED);
 
 /**
  * @deprecated Deprecated since Contao 4.9, to be removed in Contao 5.0; use the