diff --git a/core/modules/system/lib/Drupal/system/Tests/Menu/LocalTasksTest.php b/core/modules/system/lib/Drupal/system/Tests/Menu/LocalTasksTest.php
index 36ae0fa..729b4f6 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Menu/LocalTasksTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Menu/LocalTasksTest.php
@@ -141,7 +141,7 @@ protected function assertLocalTasks(array $hrefs, $level = 0) {
   }
 
   /**
-   * Tests the appearance of the plugin based local tasks.
+   * Tests the plugin based local tasks.
    */
   public function testPluginLocalTask() {
     // Verify that local tasks appear as defined in the router.
@@ -192,18 +192,18 @@ public function testPluginLocalTask() {
 
     // Ensures that the local tasks contains the proper 'provider key'
     $definitions = $this->container->get('plugin.manager.menu.local_task')->getDefinitions();
-    $this->assertEqual($definitions['menu_test.local_task_test_tasks_view_tab']['provider'], 'menu_test');
-    $this->assertEqual($definitions['menu_test.local_task_test_tasks_edit_tab']['provider'], 'menu_test');
-    $this->assertEqual($definitions['menu_test.local_task_test_tasks_settings_tab']['provider'], 'menu_test');
-    $this->assertEqual($definitions['menu_test.local_task_test_tasks_settings_sub1_tab']['provider'], 'menu_test');
-    $this->assertEqual($definitions['menu_test.local_task_test_tasks_settings_sub2_tab']['provider'], 'menu_test');
-    $this->assertEqual($definitions['menu_test.local_task_test_tasks_settings_sub3_tab']['provider'], 'menu_test');
+    $this->assertEqual($definitions['menu_local_task_test_tasks_view']['provider'], 'menu_test');
+    $this->assertEqual($definitions['menu_local_task_test_tasks_edit']['provider'], 'menu_test');
+    $this->assertEqual($definitions['menu_local_task_test_tasks_settings']['provider'], 'menu_test');
+    $this->assertEqual($definitions['menu_local_task_test_tasks_settings_sub1']['provider'], 'menu_test');
+    $this->assertEqual($definitions['menu_local_task_test_tasks_settings_sub2']['provider'], 'menu_test');
+    $this->assertEqual($definitions['menu_local_task_test_tasks_settings_sub3']['provider'], 'menu_test');
 
-    // Creating a entity which will be used in the following upcasting tests.
+    // Create an entity which will be used in the following upcasting tests.
     $entity = \Drupal::entityManager()->getStorageController('entity_test')->create(array('bundle' => 'test'));
     $entity->save();
 
-    // Checks tab sub1 exists and is active.
+    // Check the sub1 tab is the only active tab.
     $this->drupalGet('menu-local-task-test-upcasting/1/sub1');
 
     $tasks = array(
@@ -216,7 +216,8 @@ public function testPluginLocalTask() {
     $this->assertEqual(1, count($result), 'There is just a single active tab.');
     $this->assertEqual('upcasting sub1', (string) $result[0]->a, 'The sub1 tab is active.');
 
-    // Checks tab sub2 exists and is active.
+    // Switch tabs to check that the sub1 tab is no longer active and that the
+    // sub2 tab is the only active tab.
     $this->drupalGet('menu-local-task-test-upcasting/1/sub2');
 
     $tasks = array(
@@ -227,7 +228,7 @@ public function testPluginLocalTask() {
 
     $result = $this->xpath('//ul[contains(@class, "tabs")]//li[contains(@class, "active")]');
     $this->assertEqual(1, count($result), 'There is just a single active tab.');
-    $this->assertEqual('upcasting sub2', (string) $result[0]->a, 'The sub2 tab is active');
+    $this->assertEqual('upcasting sub2', (string) $result[0]->a, 'The sub2 tab is active.');
   }
 
 }
diff --git a/core/modules/system/tests/modules/menu_test/menu_test.local_tasks.yml b/core/modules/system/tests/modules/menu_test/menu_test.local_tasks.yml
index 5bdb869..7d270f3 100644
--- a/core/modules/system/tests/modules/menu_test/menu_test.local_tasks.yml
+++ b/core/modules/system/tests/modules/menu_test/menu_test.local_tasks.yml
@@ -1,54 +1,54 @@
-menu_test.local_task_test_tasks_view_tab:
+menu_local_task_test_tasks_view:
   route_name: menu_test.local_task_test_tasks_view
   title: View
-  tab_root_id: menu_test.local_task_test_tasks_view_tab
-menu_test.local_task_test_tasks_edit_tab:
+  tab_root_id: menu_local_task_test_tasks_view
+menu_local_task_test_tasks_edit:
   route_name: menu_test.local_task_test_tasks_edit
   title: Edit
-  tab_root_id: menu_test.local_task_test_tasks_view_tab
-menu_test.local_task_test_tasks_settings_tab:
+  tab_root_id: menu_local_task_test_tasks_view
+menu_local_task_test_tasks_settings:
   route_name: menu_test.local_task_test_tasks_settings
   title: Settings
-  tab_root_id: menu_test.local_task_test_tasks_view_tab
-menu_test.local_task_test_tasks_settings_sub1_tab:
+  tab_root_id: menu_local_task_test_tasks_view
+menu_local_task_test_tasks_settings_sub1:
   route_name: menu_test.local_task_test_tasks_settings_sub1
   title: sub1
-  tab_root_id: menu_test.local_task_test_tasks_view_tab
-  tab_parent_id: menu_test.local_task_test_tasks_settings_tab
+  tab_root_id: menu_local_task_test_tasks_view
+  tab_parent_id: menu_local_task_test_tasks_settings
   class: Drupal\menu_test\Plugin\Menu\LocalTask\TestTasksSettingsSub1
   weight: -10
-menu_test.local_task_test_tasks_settings_sub2_tab:
+menu_local_task_test_tasks_settings_sub2:
   route_name: menu_test.local_task_test_tasks_settings_sub2
   title: sub2
-  tab_root_id: menu_test.local_task_test_tasks_view_tab
-  tab_parent_id: menu_test.local_task_test_tasks_settings_tab
-menu_test.local_task_test_tasks_settings_sub3_tab:
+  tab_root_id: menu_local_task_test_tasks_view
+  tab_parent_id: menu_local_task_test_tasks_settings
+menu_local_task_test_tasks_settings_sub3:
   route_name: menu_test.local_task_test_tasks_settings_sub3
   title: sub3
-  tab_root_id: menu_test.local_task_test_tasks_view_tab
-  tab_parent_id: menu_test.local_task_test_tasks_settings_tab
+  tab_root_id: menu_local_task_test_tasks_view
+  tab_parent_id: menu_local_task_test_tasks_settings
   weight: 20
-menu_test.local_task_test_tasks_settings_derived_tab:
+menu_local_task_test_tasks_settings_derived:
   route_name: menu_test.local_task_test_tasks_settings_derived
   title: derived
-  tab_root_id: menu_test.local_task_test_tasks_view_tab
-  tab_parent_id: menu_test.local_task_test_tasks_settings_tab
+  tab_root_id: menu_local_task_test_tasks_view
+  tab_parent_id: menu_local_task_test_tasks_settings
   derivative: Drupal\menu_test\Plugin\Derivative\LocalTaskTest
   weight: 50
-menu_test.local_task_test_placeholder_sub1_tab:
+menu_local_task_test.placeholder_sub1:
   route_name: menu_test.local_task_test_placeholder_sub1
   title: 'placeholder sub1'
-  tab_root_id: menu_test.local_task_test_placeholder_sub1_tab
-menu_test.local_task_test_placeholder_sub2_tab:
+  tab_root_id: menu_local_task_test_placeholder_sub1
+menu_local_task_test_placeholder_sub2:
   route_name: menu_test.local_task_test_placeholder_sub2
   title: 'placeholder sub2'
-  tab_root_id: menu_test.local_task_test_placeholder_sub1_tab
-menu_test.local_task_test_upcasting_sub1_tab:
+  tab_root_id: menu_local_task_test_placeholder_sub1
+menu_local_task_test.upcasting_sub1:
   route_name: menu_test.local_task_test_upcasting_sub1
   title: 'upcasting sub1'
-  tab_root_id: menu_test.local_task_test_upcasting_sub1_tab
-menu_test.local_task_test_upcasting_sub2_tab:
+  tab_root_id: menu_local_task_test_upcasting_sub1
+menu_local_task_test_upcasting_sub2:
   route_name: menu_test.local_task_test_upcasting_sub2
   title: 'upcasting sub2'
-  tab_root_id: menu_test.local_task_test_upcasting_sub1_tab
+  tab_root_id: menu_local_task_test_upcasting_sub1
   weight: 10