diff --git a/doc/source/upgrading.rst b/doc/source/upgrading.rst
index 5d4438c57..1ee05c07f 100644
--- a/doc/source/upgrading.rst
+++ b/doc/source/upgrading.rst
@@ -31,6 +31,7 @@ particular, the following options may need to be changed if not using their
 default values:
 
 * ``kolla_openstack_release``
+* ``kolla_tag``
 * ``kolla_sources``
 * ``kolla_build_blocks``
 * ``kolla_build_customizations``