diff --git a/app/assets/javascripts/discourse/controllers/flag.js.es6 b/app/assets/javascripts/discourse/controllers/flag.js.es6
index 445dd273fa1..a5119b383e0 100644
--- a/app/assets/javascripts/discourse/controllers/flag.js.es6
+++ b/app/assets/javascripts/discourse/controllers/flag.js.es6
@@ -49,7 +49,7 @@ export default Ember.Controller.extend(ModalFunctionality, {
   }.property('post', 'flagTopic', 'model.actions_summary.@each.can_act'),
 
   staffFlagsAvailable: function() {
-    return (this.get('model.flagsAvailable').length > 1);
+    return (this.get('model.flagsAvailable') && this.get('model.flagsAvailable').length > 1);
   }.property('post', 'flagTopic', 'model.actions_summary.@each.can_act'),
 
   submitEnabled: function() {