diff --git a/koha-tmpl/intranet-tmpl/prog/en/includes/search_indexes.inc b/koha-tmpl/intranet-tmpl/prog/en/includes/search_indexes.inc
index 8c01af0f49..ea67ed0234 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/includes/search_indexes.inc
+++ b/koha-tmpl/intranet-tmpl/prog/en/includes/search_indexes.inc
@@ -1,4 +1,7 @@
 [% USE Koha %]
+[% UNLESS index %]
+    [% SET index = 0 %]
+[% END %]
 [% SET select_id = refiner ? 'refiner_idx_' _ index : 'idx_' _ index %]
 <select class="advsearch" name="idx" id="[% select_id | html %]">
     [% IF ms_kw %]