diff --git a/core/includes/menu.inc b/core/includes/menu.inc
index b75aa7f..e5310eb 100644
--- a/core/includes/menu.inc
+++ b/core/includes/menu.inc
@@ -1579,8 +1579,7 @@ function template_preprocess_menu_tree(&$variables) {
 function template_preprocess_menu_link(&$variables) {
   $element = $variables['element'];
 
-  // @todo Remove below drupal_render()?
-  $variables['sub_menu'] = ($element['#below']) ? drupal_render($element['#below']) : array();
+  $variables['sub_menu'] = $element['#below'];
   $variables['link'] = l($element['#title'], $element['#href'], $element['#localized_options']);
   $variables['wrapper_attributes'] = new Attribute($element['#attributes']);
 }
@@ -2237,15 +2236,16 @@ function theme_menu_local_tasks(&$variables) {
 }
 
 /**
- * Preprocess variables for primary and secondary local tasks.
+ * Prepares variables for primary and secondary local task templates.
  *
- * @param $variables
+ * Default template: menu-local-tasks.html.twig.
+ *
+ * @param array $variables
  *   An associative array containing:
  *   - primary: (optional) An array of local tasks (tabs).
  *   - secondary: (optional) An array of local tasks (tabs).
  *
  * @see menu_local_tasks()
- * @ingroup themeable
  */
 function template_preprocess_menu_local_tasks(&$variables) {
   $variables['primary_tasks'] = (!empty($variables['primary'])) ? drupal_render($variables['primary']) : FALSE;
diff --git a/core/modules/system/templates/menu-link.html.twig b/core/modules/system/templates/menu-link.html.twig
index 9d3146a..66082b2 100644
--- a/core/modules/system/templates/menu-link.html.twig
+++ b/core/modules/system/templates/menu-link.html.twig
@@ -4,7 +4,7 @@
  * Default theme implementation for a menu link and submenu.
  *
  * Available variables:
- * - wrapper_attributes: An array of HTML attributes for the wrapper element.
+ * - wrapper_attributes: HTML attributes for the wrapper element.
  * - link: An HTML string representing the rendered link.
  * - sub_menu: Rendered list item children of the element.
  *