diff --git a/public/app/features/alerting/alert_tab_ctrl.ts b/public/app/features/alerting/alert_tab_ctrl.ts
index 0c42c2dbe7e..546aee776a7 100644
--- a/public/app/features/alerting/alert_tab_ctrl.ts
+++ b/public/app/features/alerting/alert_tab_ctrl.ts
@@ -208,6 +208,8 @@ export class AlertTabCtrl {
           this.error = 'Currently the alerting backend only supports Graphite queries';
         } else if (this.templateSrv.variableExists(foundTarget.target)) {
           this.error = 'Template variables are not supported in alert queries';
+        } else {
+          this.error = '';
         }
       });
     }