Index: wp-includes/post.php
===================================================================
--- wp-includes/post.php	(revision 15605)
+++ wp-includes/post.php	(working copy)
@@ -2074,7 +2074,7 @@
 
 	$post = get_post($postid, $mode);
 
-	if ( 
+	if (
 		( OBJECT == $mode && empty( $post->ID ) ) ||
 		( OBJECT != $mode && empty( $post['ID'] ) )
 	)
@@ -3058,11 +3058,6 @@
 	$number = (int) $number;
 	$offset = (int) $offset;
 
-	// Make sure the post type is hierarchical
-	$hierarchical_post_types = get_post_types( array( 'hierarchical' => true ) );
-	if ( !in_array( $post_type, $hierarchical_post_types ) )
-		return false;
-
 	// Make sure we have a valid post status
 	if ( !in_array($post_status, get_post_stati()) )
 		return false;