diff --git a/plone/app/discussion/browser/stylesheets/discussion.css b/plone/app/discussion/browser/stylesheets/discussion.css
index d63b9c7..e777222 100644
--- a/plone/app/discussion/browser/stylesheets/discussion.css
+++ b/plone/app/discussion/browser/stylesheets/discussion.css
@@ -46,6 +46,7 @@
     clear: both;
     margin: 1em 0;
     overflow: auto;
+    border: 1px solid #ccc;
 }
 
 .commentBody p {