diff --git a/doc/templates/bootstrap/search.html b/doc/templates/bootstrap/search.html
index 60a6601b88..9cc6b83650 100644
--- a/doc/templates/bootstrap/search.html
+++ b/doc/templates/bootstrap/search.html
@@ -11,6 +11,7 @@
{% set title = _('Search') %}
{% block extrahead %}
+
{# this is used when loading the search index using $.ajax fails,
such as on Chrome for documents on localhost #}