diff --git a/koha-tmpl/intranet-tmpl/prog/js/datatables.js b/koha-tmpl/intranet-tmpl/prog/js/datatables.js
index a8714fbf6c..96817862cc 100644
--- a/koha-tmpl/intranet-tmpl/prog/js/datatables.js
+++ b/koha-tmpl/intranet-tmpl/prog/js/datatables.js
@@ -1163,7 +1163,10 @@ function _dt_add_filters(table_node, table_dt, filters_options = {}) {
                         if (
                             existing_search === this._id ||
                             (existing_search &&
-                                this._id.toLowerCase().match(existing_search))
+                                this._id
+                                    .toString()
+                                    .toLowerCase()
+                                    .match(existing_search))
                         ) {
                             o.prop("selected", "selected");
                         }