diff --git a/app/assets/javascripts/discourse/models/post_stream.js b/app/assets/javascripts/discourse/models/post_stream.js
index 0a38c5c8d..54d9b3e94 100644
--- a/app/assets/javascripts/discourse/models/post_stream.js
+++ b/app/assets/javascripts/discourse/models/post_stream.js
@@ -686,6 +686,9 @@ Discourse.PostStream = Em.Object.extend({
     @returns {Discourse.Post} the post from the identity map
   **/
   storePost: function(post) {
+    // Calling `Em.get(undefined` raises an error
+    if (!post) { return; }
+
     var postId = Em.get(post, 'id');
     if (postId) {
       var postIdentityMap = this.get('postIdentityMap'),
@@ -745,7 +748,7 @@ Discourse.PostStream = Em.Object.extend({
     return this.loadIntoIdentityMap(unloaded).then(function() {
       return postIds.map(function (p) {
         return postIdentityMap.get(p);
-      });
+      }).compact();
     });
   },