Index: wp-content/themes/twentythirteen/style.css
===================================================================
--- wp-content/themes/twentythirteen/style.css	(revision 24382)
+++ wp-content/themes/twentythirteen/style.css	(working copy)
@@ -2623,6 +2623,9 @@
 	background-color: transparent;
 }
 
+.widget .textwidget {
+	word-wrap: break-word;
+}
 
 /**
  * 7.0 Footer