diff --git a/src/datasource-zabbix/query.controller.js b/src/datasource-zabbix/query.controller.js
index bd35da3..5b609dc 100644
--- a/src/datasource-zabbix/query.controller.js
+++ b/src/datasource-zabbix/query.controller.js
@@ -60,7 +60,6 @@ export class ZabbixQueryController extends QueryCtrl {
         application: { filter: "" },
         item: { filter: "" },
         functions: [],
-        refId: "A"
       };
       _.defaults(target, targetDefaults);