diff --git a/reference/forms/types/enum.rst b/reference/forms/types/enum.rst
index c91111e4284..d6dd8f97018 100644
--- a/reference/forms/types/enum.rst
+++ b/reference/forms/types/enum.rst
@@ -78,6 +78,8 @@ These options inherit from the :doc:`ChoiceType </reference/forms/types/choice>`
 
 .. include:: /reference/forms/types/options/expanded.rst.inc
 
+.. include:: /reference/forms/types/options/group_by.rst.inc
+
 .. include:: /reference/forms/types/options/multiple.rst.inc
 
 .. include:: /reference/forms/types/options/placeholder.rst.inc