diff --git a/boards/static/js/thread_update.js b/boards/static/js/thread_update.js
--- a/boards/static/js/thread_update.js
+++ b/boards/static/js/thread_update.js
@@ -25,6 +25,9 @@
 
 var CLASS_POST = '.post'
 
+var POST_ADDED = 0;
+var POST_UPDATED = 1;
+
 var wsUser = '';
 
 var unreadPosts = 0;
@@ -102,12 +105,15 @@ function getThreadDiff() {
         data,
         function(data) {
             var updatedPosts = data.updated;
+            var addedPostCount = 0;
 
             for (var i = 0; i < updatedPosts.length; i++) {
                 var postText = updatedPosts[i];
                 var post = $(postText);
 
-                updatePost(post);
+                if (updatePost(post) == POST_ADDED) {
+                    addedPostCount++;
+                }
             }
 
             var hasMetaUpdates = updatedPosts.length > 0;
@@ -115,6 +121,9 @@ function getThreadDiff() {
                 updateMetadataPanel();
             }
 
+            updateBumplimitProgress(addedPostCount);
+            showNewPostsTitle(addedPostCount);
+
             // TODO Process removed posts if any
             $('.metapanel').attr('data-last-update', data.last_update);
         },
@@ -139,8 +148,12 @@ function updatePost(postHtml) {
     // If the post already exists, replace it. Otherwise add as a new one.
     var existingPosts = threadBlock.children('.post[id=' + postId + ']');
 
+    var type;
+
     if (existingPosts.size() > 0) {
         existingPosts.replaceWith(post);
+
+        type = POST_UPDATED;
     } else {
         post.appendTo(threadBlock);
 
@@ -148,11 +161,12 @@ function updatePost(postHtml) {
             scrollToBottom();
         }
 
-        updateBumplimitProgress(1);
-        showNewPostsTitle(1);
+        type = POST_ADDED;
     }
 
     processNewPost(post);
+
+    return type;
 }
 
 /**