Index: wp-includes/update.php
===================================================================
--- wp-includes/update.php	(revision 11110)
+++ wp-includes/update.php	(working copy)
@@ -283,16 +283,22 @@
 	wp_update_themes( );
 }
 
-add_action( 'init', '_maybe_update_core' );
+if ( is_admin() ) {
+	add_action( 'admin_init', '_maybe_update_core' );
+	add_action( 'admin_init', '_maybe_update_plugins' );
+	add_action( 'admin_init', '_maybe_update_themes' );
+} else {
+	add_action( 'shutdown', '_maybe_update_core', 1 );
+	add_action( 'shutdown', '_maybe_update_plugins', 1 );
+	add_action( 'shutdown', '_maybe_update_themes', 1 );
+}
 
 add_action( 'load-plugins.php', 'wp_update_plugins' );
 add_action( 'load-update.php', 'wp_update_plugins' );
-add_action( 'admin_init', '_maybe_update_plugins' );
 add_action( 'wp_update_plugins', 'wp_update_plugins' );
 
 add_action( 'load-themes.php', 'wp_update_themes' );
 add_action( 'load-update.php', 'wp_update_themes' );
-add_action( 'admin_init', '_maybe_update_themes' );
 add_action( 'wp_update_themes', 'wp_update_themes' );
 
 if ( !wp_next_scheduled('wp_update_plugins') && !defined('WP_INSTALLING') )
@@ -302,4 +308,4 @@
 if ( !wp_next_scheduled('wp_update_themes') && !defined('WP_INSTALLING') )
 	wp_schedule_event(time(), 'twicedaily', 'wp_update_themes');
 
-?>
+?>
\ No newline at end of file