Index: src/wp-admin/css/wp-admin.css
===================================================================
--- src/wp-admin/css/wp-admin.css	(revision 26844)
+++ src/wp-admin/css/wp-admin.css	(working copy)
@@ -2243,6 +2243,7 @@
 	height: 1.3em;
 	line-height: 1.1em;
 	display: block;
+	text-align: center;
 	text-decoration: none;
 	padding: 0 0 6px;
 	cursor: pointer;