diff --git a/app/assets/javascripts/discourse/components/scrolling-post-stream.js.es6 b/app/assets/javascripts/discourse/components/scrolling-post-stream.js.es6
index 0e8fc7751cc..83cbcbebb28 100644
--- a/app/assets/javascripts/discourse/components/scrolling-post-stream.js.es6
+++ b/app/assets/javascripts/discourse/components/scrolling-post-stream.js.es6
@@ -43,7 +43,7 @@ export default MountWidget.extend({
 
     let windowTop = $w.scrollTop();
 
-    const $posts = this.$('article.boxed');
+    const $posts = this.$('.onscreen-post');
     const viewportTop = windowTop - slack;
     const topView = findTopView($posts, viewportTop, 0, $posts.length-1);
 
diff --git a/app/assets/javascripts/discourse/widgets/post-small-action.js.es6 b/app/assets/javascripts/discourse/widgets/post-small-action.js.es6
index e4590e1d409..699e97dd0d5 100644
--- a/app/assets/javascripts/discourse/widgets/post-small-action.js.es6
+++ b/app/assets/javascripts/discourse/widgets/post-small-action.js.es6
@@ -23,7 +23,7 @@ const icons = {
 };
 
 export default createWidget('post-small-action', {
-  tagName: 'div.small-action.clearfix',
+  tagName: 'div.small-action.onscreen-post.clearfix',
 
   html(attrs) {
     const contents = [];
diff --git a/app/assets/javascripts/discourse/widgets/post.js.es6 b/app/assets/javascripts/discourse/widgets/post.js.es6
index 06916e942d0..26ed9f4e4b7 100644
--- a/app/assets/javascripts/discourse/widgets/post.js.es6
+++ b/app/assets/javascripts/discourse/widgets/post.js.es6
@@ -295,7 +295,7 @@ createWidget('post-body', {
 });
 
 createWidget('post-article', {
-  tagName: 'article.boxed',
+  tagName: 'article.boxed.onscreen-post',
   buildKey: attrs => `post-article-${attrs.id}`,
 
   defaultState() {