Index: wp-content/themes/twentythirteen/style.css
===================================================================
--- wp-content/themes/twentythirteen/style.css	(revision 24245)
+++ wp-content/themes/twentythirteen/style.css	(working copy)
@@ -2287,6 +2287,10 @@
 	font-style: normal;
 }
 
+.comment-author .fn {
+	word-wrap: break-word;
+}
+
 .says {
 	display: none;
 }