diff --git a/src/Symfony/Component/Workflow/MarkingStore/MethodMarkingStore.php b/src/Symfony/Component/Workflow/MarkingStore/MethodMarkingStore.php
index e2e61e7278..e51ac0afa9 100644
--- a/src/Symfony/Component/Workflow/MarkingStore/MethodMarkingStore.php
+++ b/src/Symfony/Component/Workflow/MarkingStore/MethodMarkingStore.php
@@ -21,7 +21,7 @@ use Symfony\Component\Workflow\Marking;
  *
  * @author Grégoire Pineau <lyrixx@lyrixx.info>
  */
-class MethodMarkingStore implements MarkingStoreInterface
+final class MethodMarkingStore implements MarkingStoreInterface
 {
     private $singleState;
     private $property;