diff --git a/public/app/features/alerting/AlertTabCtrl.ts b/public/app/features/alerting/AlertTabCtrl.ts
index 0101e8e516c..b969d8269ca 100644
--- a/public/app/features/alerting/AlertTabCtrl.ts
+++ b/public/app/features/alerting/AlertTabCtrl.ts
@@ -241,6 +241,10 @@ export class AlertTabCtrl {
   }
 
   checkFrequency() {
+    if (!this.alert.frequency) {
+      return;
+    }
+
     this.frequencyWarning = '';
 
     try {