diff --git a/src/wp-includes/post-template.php b/src/wp-includes/post-template.php
index ddb5180117..939c8f617e 100644
--- a/src/wp-includes/post-template.php
+++ b/src/wp-includes/post-template.php
@@ -1524,8 +1524,7 @@ function walk_page_tree( $pages, $depth, $current_page, $r ) {
 		}
 	}
 
-	$args = array( $pages, $depth, $r, $current_page );
-	return call_user_func_array( array( $walker, 'walk' ), $args );
+	return $walker->walk( $pages, $depth, $r, $current_page );
 }
 
 /**