diff --git a/src/Symfony/Component/Form/DependencyInjection/FormPass.php b/src/Symfony/Component/Form/DependencyInjection/FormPass.php
index 0c6306672d2e..358bf71205b7 100644
--- a/src/Symfony/Component/Form/DependencyInjection/FormPass.php
+++ b/src/Symfony/Component/Form/DependencyInjection/FormPass.php
@@ -102,9 +102,9 @@ private function processFormTypeExtensions(ContainerBuilder $container)
             } elseif (method_exists($serviceDefinition->getClass(), 'getExtendedTypes')) {
                 $extendsTypes = false;
 
+                $typeExtensionsClasses[] = $serviceDefinition->getClass();
                 foreach ($serviceDefinition->getClass()::getExtendedTypes() as $extendedType) {
                     $typeExtensions[$extendedType][] = new Reference($serviceId);
-                    $typeExtensionsClasses[] = $serviceDefinition->getClass();
                     $extendsTypes = true;
                 }