diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/config/form.xml b/src/Symfony/Bundle/FrameworkBundle/Resources/config/form.xml
index d23a06fcf1deb..d75dff1666ac2 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Resources/config/form.xml
+++ b/src/Symfony/Bundle/FrameworkBundle/Resources/config/form.xml
@@ -184,7 +184,7 @@
             <tag name="form.type_extension" extended-type="Symfony\Component\Form\Extension\Core\Type\SubmitType" />
         </service>
         <service id="form.type_extension.upload.validator" class="Symfony\Component\Form\Extension\Validator\Type\UploadValidatorExtension">
-            <tag name="form.type_extension" alias="form" />
+            <tag name="form.type_extension" alias="form" extended-type="Symfony\Component\Form\Extension\Core\Type\FormType" />
             <argument type="service" id="translator"/>
             <argument type="string">%validator.translation_domain%</argument>
         </service>