diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/query/Sql.php b/core/modules/views/lib/Drupal/views/Plugin/views/query/Sql.php
index 24d7dcb..95dbb13 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/query/Sql.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/query/Sql.php
@@ -587,7 +587,7 @@ function ensure_table($table, $relationship = NULL, JoinPluginBase $join = NULL)
    * query they will be added, but additional copies will NOT be added
    * if the table is already there.
    */
-  function ensurePath($table, $relationship = NULL, $join = NULL, $traced = array(), $add = array()) {
+  protected function ensurePath($table, $relationship = NULL, $join = NULL, $traced = array(), $add = array()) {
     if (!isset($relationship)) {
       $relationship = $this->view->storage->get('base_table');
     }