diff --git a/lib/main.html b/lib/main.html
index 64add4068..c47da9e48 100644
--- a/lib/main.html
+++ b/lib/main.html
@@ -117,6 +117,7 @@
   <script src="../node_modules/codemirror/addon/search/jump-to-line.js"></script>
 
   <script src="../node_modules/codemirror/addon/fold/brace-fold.js"></script>
+  <script src="../node_modules/codemirror/addon/fold/markdown-fold.js"></script>
   <script src="../node_modules/codemirror/addon/fold/foldgutter.js"></script>
   <script src="../node_modules/codemirror/addon/fold/foldcode.js"></script>