Index: wp-includes/script-loader.php
===================================================================
--- wp-includes/script-loader.php	(revision 18490)
+++ wp-includes/script-loader.php	(working copy)
@@ -553,7 +553,7 @@
  */
 function wp_just_in_time_script_localization() {
 
-	wp_add_script_data( 'autosave', 'autosaveL10n', array(
+	wp_localize_script( 'autosave', 'autosaveL10n', array(
 		'autosaveInterval' => AUTOSAVE_INTERVAL,
 		'savingText' => __('Saving Draft…'),
 		'saveAlert' => __('The changes you made will be lost if you navigate away from this page.')