diff --git a/templates/mailman-django/confirm_dialog.html b/templates/mailman-django/confirm_dialog.html
index e0773b9..e9e1b2c 100644
--- a/templates/mailman-django/confirm_dialog.html
+++ b/templates/mailman-django/confirm_dialog.html
@@ -2,7 +2,7 @@
 {% load i18n %}
 
 {% block header %}
-    <div class="mm_box">
+    <div class="mm_box mm_clear">
         <div class="mm_boxHeader">{% trans "Please confirm this action" %}</div>
         <form action="{{submit_url}}" method="post">
             <div class="field">