diff --git a/src/pages/EditMonitor.vue b/src/pages/EditMonitor.vue
index 48117c8f6..2ee2e66ae 100644
--- a/src/pages/EditMonitor.vue
+++ b/src/pages/EditMonitor.vue
@@ -3730,7 +3730,7 @@ message HealthCheckResponse {
                 }
             }
 
-            if (newSubtype !== oldSubtype) {
+            if (oldSubtype && newSubtype !== oldSubtype) {
                 if (newSubtype === "ping") {
                     this.monitor.protocol = "ICMP";
                     this.monitor.port = "80";