diff --git a/src/Symfony/Bundle/SecurityBundle/Resources/config/security.xml b/src/Symfony/Bundle/SecurityBundle/Resources/config/security.xml
index 402b01af6c347..26db528aed550 100644
--- a/src/Symfony/Bundle/SecurityBundle/Resources/config/security.xml
+++ b/src/Symfony/Bundle/SecurityBundle/Resources/config/security.xml
@@ -96,6 +96,7 @@
         <service id="security.role_hierarchy" class="Symfony\Component\Security\Core\Role\RoleHierarchy">
             <argument>%security.role_hierarchy.roles%</argument>
         </service>
+        <service id="Symfony\Component\Security\Core\Role\RoleHierarchyInterface" alias="security.role_hierarchy" />
 
 
         <!-- Security Voters -->