Index: wp-includes/post-template.php
===================================================================
--- wp-includes/post-template.php	(revision 12005)
+++ wp-includes/post-template.php	(working copy)
@@ -745,7 +745,7 @@
 		'child_of' => 0, 'exclude' => '',
 		'title_li' => __('Pages'), 'echo' => 1,
 		'authors' => '', 'sort_column' => 'menu_order, post_title',
-		'link_before' => '', 'link_after' => ''
+		'link_before' => '', 'link_after' => '', 'walker' => '',
 	);
 
 	$r = wp_parse_args( $args, $defaults );