Index: wp-includes/functions.php
===================================================================
--- wp-includes/functions.php	(revision 21921)
+++ wp-includes/functions.php	(working copy)
@@ -903,7 +903,7 @@
 	$headers = array(
 		'Expires' => 'Wed, 11 Jan 1984 05:00:00 GMT',
 		'Last-Modified' => gmdate( 'D, d M Y H:i:s' ) . ' GMT',
-		'Cache-Control' => 'no-cache, must-revalidate, max-age=0',
+		'Cache-Control' => 'no-cache, no-store, must-revalidate, max-age=0',
 		'Pragma' => 'no-cache',
 	);