diff --git a/lms/static/coffee/src/discussion/views/discussion_thread_show_view.coffee b/lms/static/coffee/src/discussion/views/discussion_thread_show_view.coffee
index bf7169bf96..cd164f2689 100644
--- a/lms/static/coffee/src/discussion/views/discussion_thread_show_view.coffee
+++ b/lms/static/coffee/src/discussion/views/discussion_thread_show_view.coffee
@@ -44,7 +44,7 @@ class @DiscussionThreadShowView extends DiscussionContentView
 
   convertMath: ->
     element = @$(".post-body")
-    element.html DiscussionUtil.postMathJaxProcessor(element.html())
+    element.html DiscussionUtil.postMathJaxProcessor DiscussionUtil.markdownWithHighlight element.html()
     MathJax.Hub.Queue ["Typeset", MathJax.Hub, element[0]]
 
   toggleVote: (event) ->