From 1636e8873bf81fc3d47099a949856d93d7a125cb Mon Sep 17 00:00:00 2001
From: Sofia Papagiannaki <papagian@users.noreply.github.com>
Date: Thu, 16 Jan 2020 17:38:49 +0200
Subject: [PATCH] Fix TypeScript error (#21545)

---
 public/app/features/alerting/AlertTabCtrl.ts | 4 ++++
 1 file changed, 4 insertions(+)

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 {