diff --git a/phpBB/styles/prosilver/template/ucp_pm_viewfolder.html b/phpBB/styles/prosilver/template/ucp_pm_viewfolder.html
index c5078df268..9cbff64a6a 100644
--- a/phpBB/styles/prosilver/template/ucp_pm_viewfolder.html
+++ b/phpBB/styles/prosilver/template/ucp_pm_viewfolder.html
@@ -53,7 +53,7 @@
 				</dl>
 			</li>
 		</ul>
-		<ul class="topiclist cplist pmlist two-columns">
+		<ul class="topiclist cplist pmlist <!-- IF S_SHOW_RECIPIENTS -->missing-column<!-- ELSE -->two-columns<!-- ENDIF -->">
 
 		<!-- BEGIN messagerow -->
 			<li class="row<!-- IF messagerow.S_ROW_COUNT is odd --> bg1<!-- ELSE --> bg2<!-- ENDIF --><!-- IF messagerow.PM_CLASS --> {messagerow.PM_CLASS}<!-- ENDIF -->">