diff --git a/wp-includes/post.php b/wp-includes/post.php
index f62183006f..a76ec59baa 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -2401,7 +2401,7 @@ function &get_page_children($page_id, $pages) {
 function &get_page_hierarchy( &$pages, $page_id = 0 ) {
 
 	if ( empty( $pages ) ) {
-		$result = null;
+		$result = array();
 		return $result;
 	}