Index: src/wp-admin/press-this.php
===================================================================
--- src/wp-admin/press-this.php	(revision 30083)
+++ src/wp-admin/press-this.php	(working copy)
@@ -638,7 +638,7 @@
 			$content .= $selection;
 
 		if ( $url ) {
-			$content .= '<p>';
+			$content .= '<p class="wppt-source">';
 
 			if ( $selection )
 				$content .= __('via ');