diff --git a/app/assets/javascripts/discourse/controllers/topic.js.es6 b/app/assets/javascripts/discourse/controllers/topic.js.es6
index 23c803e9954..71b0eabfb9f 100644
--- a/app/assets/javascripts/discourse/controllers/topic.js.es6
+++ b/app/assets/javascripts/discourse/controllers/topic.js.es6
@@ -233,8 +233,8 @@ export default Ember.Controller.extend(SelectedPostsCount, BufferedContent, {
       }
       if (post) {
         return post.toggleBookmark().catch(function(error) {
-          if (error && error.responseText) {
-            bootbox.alert($.parseJSON(error.responseText).errors[0]);
+          if (error && error.jqXHR && error.jqXHR.responseText) {
+            bootbox.alert($.parseJSON(error.jqXHR.responseText).errors[0]);
           } else {
             bootbox.alert(I18n.t('generic_error'));
           }