Index: src/wp-admin/css/themes.css
===================================================================
--- src/wp-admin/css/themes.css	(revision 37634)
+++ src/wp-admin/css/themes.css	(working copy)
@@ -721,6 +721,8 @@
 	font-weight: 100;
 	margin: 10px 0 0;
 	line-height: 1.3;
+	word-wrap: break-word;
+	overflow-wrap: break-word;
 }
 
 .theme-overlay .theme-version {