diff --git a/after/ftplugin/markdown.vim b/after/ftplugin/markdown.vim
index cac978a..680892d 100644
--- a/after/ftplugin/markdown.vim
+++ b/after/ftplugin/markdown.vim
@@ -7,6 +7,7 @@ setlocal foldmethod=expr
 setlocal foldexpr=MarkdownFold(v:lnum)
 setlocal conceallevel=2
 setlocal concealcursor=n
+setlocal commentstring=<!--%s-->
 
 function! MarkdownFold(lnum)
   let l:line = getline(a:lnum)