diff --git a/tests/DependencyInjection/Core23DompdfExtensionTest.php b/tests/DependencyInjection/Core23DompdfExtensionTest.php
index <HASH>..<HASH> 100644
--- a/tests/DependencyInjection/Core23DompdfExtensionTest.php
+++ b/tests/DependencyInjection/Core23DompdfExtensionTest.php
@@ -31,7 +31,7 @@ final class Core23DompdfExtensionTest extends AbstractExtensionTestCase
         ]);
     }
 
-    protected function getContainerExtensions()
+    protected function getContainerExtensions(): array
     {
         return [
             new Core23DompdfExtension(),
[TEST] Added return types