diff --git a/core/lib/Drupal/Core/Menu/LocalTaskManager.php b/core/lib/Drupal/Core/Menu/LocalTaskManager.php
index a171a80..55098e1 100644
--- a/core/lib/Drupal/Core/Menu/LocalTaskManager.php
+++ b/core/lib/Drupal/Core/Menu/LocalTaskManager.php
@@ -184,7 +184,12 @@ public function getLocalTasksForRoute($route_name) {
         $children = array();
         foreach ($definitions as $plugin_id => $task_info) {
           if ($route_name == $task_info['route_name']) {
-            $base_routes[$task_info['base_route']] = $task_info['base_route'];
+            if(!empty($task_info['base_route'])) {
+              $base_routes[$task_info['base_route']] = $task_info['base_route'];
+            }
+            elseif(!empty($task_info['parent_id'])) {
+              $base_routes[$task_info['parent_id']] = $task_info['parent_id'];
+            }
             // Tabs that link to the current route are viable parents
             // and their parent and children should be visible also.
             // @todo - this only works for 2 levels of tabs.