diff --git a/searx/static/js/search_on_category_select.js b/searx/static/js/search_on_category_select.js
index 6156ca4e8..990211690 100644
--- a/searx/static/js/search_on_category_select.js
+++ b/searx/static/js/search_on_category_select.js
@@ -1,5 +1,5 @@
 $(document).ready(function() {
-    if($('#q')) {
+    if($('#q').length) {
         $('#categories label').click(function(e) {
             $('#categories input[type="checkbox"]').each(function(i, checkbox) {
                 $(checkbox).prop('checked', false);