diff --git a/core/modules/system/lib/Drupal/system/SystemManager.php b/core/modules/system/lib/Drupal/system/SystemManager.php
index 7397aa1..619642e 100644
--- a/core/modules/system/lib/Drupal/system/SystemManager.php
+++ b/core/modules/system/lib/Drupal/system/SystemManager.php
@@ -179,10 +179,11 @@ public function getBlockContents() {
   /**
    * Provide a single block on the administration overview page.
    *
-   * @param $item
+   * @param \Drupal\menu_link\MenuLinkInterface|array $item
    *   The menu item to be displayed.
    *
    * @return array
+   *   An array of menu items, as expected by theme_admin_block_content().
    */
   public function getAdminBlock($item) {
     // If we are calling this function for a menu item that corresponds to a