diff --git a/common/static/coffee/src/discussion/views/discussion_thread_list_view.coffee b/common/static/coffee/src/discussion/views/discussion_thread_list_view.coffee
index f9710c7077..c36b3b72d7 100644
--- a/common/static/coffee/src/discussion/views/discussion_thread_list_view.coffee
+++ b/common/static/coffee/src/discussion/views/discussion_thread_list_view.coffee
@@ -64,10 +64,8 @@ if Backbone?
 
       sidebar = $(".sidebar")
       if scrollTop > discussionsBodyTop - @sidebar_padding
-        sidebar.addClass('fixed');
-        sidebar.css('top', @sidebar_padding);
+        sidebar.css('top', scrollTop - discussionsBodyTop + @sidebar_padding);
       else
-        sidebar.removeClass('fixed');
         sidebar.css('top', '0');
 
       sidebarWidth = .31 * $(".discussion-body").width();
diff --git a/lms/static/sass/_discussion.scss b/lms/static/sass/_discussion.scss
index 9cb6708b8f..fa0df25ebc 100644
--- a/lms/static/sass/_discussion.scss
+++ b/lms/static/sass/_discussion.scss
@@ -690,14 +690,6 @@ body.discussion {
     border-radius: 3px;
     background: #f6f6f6;
     box-shadow: 0 1px 2px rgba(0, 0, 0, .05);
-
-    &.fixed {
-      @include box-sizing(border-box);
-      position: fixed;
-      top: 0px;
-      width: 32%;
-    }
-
   }
 
   .browse-search {
@@ -1283,10 +1275,6 @@ body.discussion {
     border-radius: 3px;
     background: $white;
     box-shadow: 0 1px 2px rgba(0, 0, 0, .05);
-
-    &.sidebar-fixed {
-      margin-left: 32%;
-    }
   }
 
   .blank-slate {