diff --git a/docs/ref/templates/builtins.txt b/docs/ref/templates/builtins.txt
index eaa576ef15..1767b5ba07 100644
--- a/docs/ref/templates/builtins.txt
+++ b/docs/ref/templates/builtins.txt
@@ -493,7 +493,7 @@ how ``x in y`` will be interpreted::
     {% endif %}
 
 ``not in`` operator
-~~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^
 
 Not contained within.  This is the negation of the ``in`` operator.