diff --git a/app/assets/javascripts/discourse/models/topic_details.js b/app/assets/javascripts/discourse/models/topic_details.js
index 40bb8859234..cf29e9e12f9 100644
--- a/app/assets/javascripts/discourse/models/topic_details.js
+++ b/app/assets/javascripts/discourse/models/topic_details.js
@@ -34,7 +34,7 @@ Discourse.TopicDetails = Discourse.Model.extend({
 
 
   notificationReasonText: function() {
-    var locale_string = "topic.notifications.reasons." + this.get('notification_level');
+    var locale_string = "topic.notifications.reasons." + (this.get('notification_level') || 1);
     if (typeof this.get('notifications_reason_id') === 'number') {
       locale_string += "_" + this.get('notifications_reason_id');
     }
diff --git a/app/assets/javascripts/discourse/views/buttons/notifications_button.js b/app/assets/javascripts/discourse/views/buttons/notifications_button.js
index c71de91263a..bf48e0b1565 100644
--- a/app/assets/javascripts/discourse/views/buttons/notifications_button.js
+++ b/app/assets/javascripts/discourse/views/buttons/notifications_button.js
@@ -21,7 +21,7 @@ Discourse.NotificationsButton = Discourse.DropdownButtonView.extend({
 
   text: function() {
     var key = (function() {
-      switch (this.get('topic.details.notification_level')) {
+      switch (this.get('topic.details.notification_level') || 1) {
         case Discourse.Topic.NotificationLevel.WATCHING: return 'watching';
         case Discourse.Topic.NotificationLevel.TRACKING: return 'tracking';
         case Discourse.Topic.NotificationLevel.REGULAR: return 'regular';