diff --git a/cookbook/form/unit_testing.rst b/cookbook/form/unit_testing.rst
index 879ea97e1ed..5ad0aa45f14 100644
--- a/cookbook/form/unit_testing.rst
+++ b/cookbook/form/unit_testing.rst
@@ -133,6 +133,8 @@ make sure the ``FormRegistry`` uses the created instance::
         {
             // mock any dependencies
             $this->entityManager = $this->getMock('Doctrine\Common\Persistence\ObjectManager');
+
+            parent::setUp();
         }
 
         protected function getExtensions()