diff --git a/admin_interface/static/admin_interface/508/dropdown-filter.js b/admin_interface/static/admin_interface/508/dropdown-filter.js
index 0115ef2..cac1591 100644
--- a/admin_interface/static/admin_interface/508/dropdown-filter.js
+++ b/admin_interface/static/admin_interface/508/dropdown-filter.js
@@ -40,7 +40,7 @@ if (typeof (django) !== 'undefined' && typeof (django.jQuery) !== 'undefined') {
                   selected = selected.concat(option.value, '%2C')
                 }
               }
-              selected = selected.replace(/,+$/, "")
+              selected = selected.substring(0, selected.lastIndexOf('%2C'))
               if (selected !== '') {
                 query = query.concat(conjunction, filter.options[0].getAttribute('key'), '=', selected)
               }