diff --git a/docs/en/reference/inheritance-mapping.rst b/docs/en/reference/inheritance-mapping.rst
index 663c8901ed3..9a0d3c208d3 100644
--- a/docs/en/reference/inheritance-mapping.rst
+++ b/docs/en/reference/inheritance-mapping.rst
@@ -601,5 +601,5 @@ Querying for the staffs without getting any technicians can be achieved by this
 .. code-block:: php
 
     <?php
-    $query = $em->createQuery("SELECT staff FROM MyProject\Model\Staff staff WHERE staff INSTANCE OF MyProject\Model\Staff");
+    $query = $em->createQuery("SELECT staff FROM MyProject\Model\Staff staff WHERE staff NOT INSTANCE OF MyProject\Model\Technician");
     $staffs = $query->getResult();