Index: ms-upgrade-site.php
===================================================================
--- ms-upgrade-site.php	(revision 12890)
+++ ms-upgrade-site.php	(working copy)
@@ -34,7 +34,7 @@
 			foreach ( (array) $blogs as $details ) {
 				if ( $details['spam'] == 0 && $details['deleted'] == 0 && $details['archived'] == 0 ) {
 					$blog_prefix = $wpdb->get_blog_prefix( $details[ 'blog_id' ] );
-					$siteurl = $wpdb->get_var( "SELECT option_value from {$blog_prefix}options WHERE option_name = 'siteurl'" );
+					$siteurl = apply_filters('ms_upgrade_siteurl',$wpdb->get_var( "SELECT option_value from {$blog_prefix}options WHERE option_name = 'siteurl'" ));
 					echo "<li>$siteurl</li>";
 					$response = wp_remote_get( trailingslashit( $siteurl ) . "wp-admin/upgrade.php?step=1", array( 'timeout' => 120, 'httpversion' => '1.1' ) );
 					if ( is_wp_error( $response ) )