diff --git a/core/modules/book/lib/Drupal/book/BookManager.php b/core/modules/book/lib/Drupal/book/BookManager.php
index 0497d85..91989da 100644
--- a/core/modules/book/lib/Drupal/book/BookManager.php
+++ b/core/modules/book/lib/Drupal/book/BookManager.php
@@ -921,7 +921,7 @@ protected function _menu_tree_check_access(&$tree) {
           $this->_menu_tree_check_access($tree[$key]['below']);
         }
         // The weights are made a uniform 5 digits by adding 50000 as an offset.
-        // After _menu_link_translate(), $item['title'] has the localized link title.
+        // After bookLinkTranslate(), $item['title'] has the translated title.
         // Adding the mlid to the end of the index insures that it is unique.
         $new_tree[(50000 + $item['weight']) . ' ' . $item['title'] . ' ' . $item['nid']] = $tree[$key];
       }