diff --git a/framework/core/js/forum/src/components/PostStream.js b/framework/core/js/forum/src/components/PostStream.js
index 4ce6b6040..d18cec577 100644
--- a/framework/core/js/forum/src/components/PostStream.js
+++ b/framework/core/js/forum/src/components/PostStream.js
@@ -212,6 +212,7 @@ class PostStream extends Component {
         attrs['data-time'] = time.toISOString();
         attrs['data-number'] = post.number();
         attrs['data-id'] = post.id();
+        attrs['data-type'] = post.contentType();
 
         // If the post before this one was more than 4 hours ago, we will
         // display a 'time gap' indicating how long it has been in between
diff --git a/framework/core/js/forum/src/components/PostStreamScrubber.js b/framework/core/js/forum/src/components/PostStreamScrubber.js
index 61a25f1f0..3e00f6a0e 100644
--- a/framework/core/js/forum/src/components/PostStreamScrubber.js
+++ b/framework/core/js/forum/src/components/PostStreamScrubber.js
@@ -25,6 +25,13 @@ export default class PostStreamScrubber extends Component {
      */
     this.index = 0;
 
+    /**
+     * The index of the comment that is currently at the top of the viewport.
+     *
+     * @type {Number}
+     */
+    this.commentsIndex = 0;
+
     /**
      * The number of posts that are currently visible in the viewport.
      *
@@ -39,16 +46,6 @@ export default class PostStreamScrubber extends Component {
      */
     this.description = '';
 
-    /**
-     * The integer index of the last item that is visible in the viewport. This
-     * is displayed on the scrubber (i.e. X of 100 posts).
-     *
-     * @return {Integer}
-     */
-    this.visibleIndex = computed('index', 'visible', 'count', function(index, visible, count) {
-      return Math.min(count, Math.ceil(Math.max(0, index) + visible));
-    });
-
     // When the post stream begins loading posts at a certain index, we want our
     // scrubber scrollbar to jump to that position.
     this.props.stream.on('unpaused', this.handlers.streamWasUnpaused = this.streamWasUnpaused.bind(this));
@@ -71,8 +68,8 @@ export default class PostStreamScrubber extends Component {
     const unreadPercent = Math.min(count - this.index, unreadCount) / count;
 
     const viewing = app.translator.transChoice('core.forum.post_scrubber.viewing_text', count, {
-      index: <span className="Scrubber-index">{retain || formatNumber(this.visibleIndex())}</span>,
-      count: <span className="Scrubber-count">{formatNumber(count)}</span>
+      index: <span className="Scrubber-index">{retain || formatNumber(this.commentsIndex)}</span>,
+      count: <span className="Scrubber-count">{formatNumber(this.commentsCount())}</span>
     });
 
     function styleUnread(element, isInitialized, context) {
@@ -155,6 +152,15 @@ export default class PostStreamScrubber extends Component {
     return this.props.stream.count();
   }
 
+  /**
+   * Get the number of comments in the discussion.
+   *
+   * @return {Integer}
+   */
+  commentsCount() {
+    return this.props.stream.discussion.commentsCount();
+  }
+
   /**
    * When the stream is unpaused, update the scrubber to reflect its position.
    */
@@ -200,6 +206,7 @@ export default class PostStreamScrubber extends Component {
     const marginTop = stream.getMarginTop();
     const viewportTop = scrollTop + marginTop;
     const viewportHeight = $(window).height() - marginTop;
+    const viewportBottom = viewportTop + viewportHeight;
 
     // Before looping through all of the posts, we reset the scrollbar
     // properties to a 'default' state. These values reflect what would be
@@ -207,6 +214,7 @@ export default class PostStreamScrubber extends Component {
     // and the viewport had a height of 0.
     const $items = stream.$('> .PostStream-item[data-index]');
     let index = $items.first().data('index') || 0;
+    let commentsIndex = 0;
     let visible = 0;
     let period = '';
 
@@ -218,6 +226,13 @@ export default class PostStreamScrubber extends Component {
       const top = $this.offset().top;
       const height = $this.outerHeight(true);
 
+      // If an item is comment and is above the top of the viewport,
+      // or within the viewport or more than 50% of it is visible,
+      // update the commentIndex
+      if($this.data('type') == 'comment' && top < viewportBottom && ((viewportBottom - top)/height) > 0.5) {
+        commentsIndex++;
+      }
+
       // If this item is above the top of the viewport, skip to the next
       // post. If it's below the bottom of the viewport, break out of the
       // loop.
@@ -253,6 +268,7 @@ export default class PostStreamScrubber extends Component {
     });
 
     this.index = index;
+    this.commentsIndex = commentsIndex;
     this.visible = visible;
     this.description = period ? moment(period).format('MMMM YYYY') : '';
   }
@@ -328,7 +344,7 @@ export default class PostStreamScrubber extends Component {
     const visible = this.visible || 1;
 
     const $scrubber = this.$();
-    $scrubber.find('.Scrubber-index').text(formatNumber(this.visibleIndex()));
+    $scrubber.find('.Scrubber-index').text(formatNumber(this.commentsIndex));
     $scrubber.find('.Scrubber-description').text(this.description);
     $scrubber.toggleClass('disabled', this.disabled());