diff --git a/app/helpers/attachments_helper.rb b/app/helpers/attachments_helper.rb
index d03997c4b..731d86839 100644
--- a/app/helpers/attachments_helper.rb
+++ b/app/helpers/attachments_helper.rb
@@ -88,7 +88,7 @@ module AttachmentsHelper
 
   def render_file_content(attachment, content)
     if attachment.is_markdown?
-      render :partial => 'common/markup', :locals => {:markup_text_formatting => 'markdown', :markup_text => content}
+      render :partial => 'common/markup', :locals => {:markup_text_formatting => 'common_mark', :markup_text => content}
     elsif attachment.is_textile?
       render :partial => 'common/markup', :locals => {:markup_text_formatting => 'textile', :markup_text => content}
     else