diff --git a/core/modules/simpletest/src/TestDiscovery.php b/core/modules/simpletest/src/TestDiscovery.php
index 50e19f0..d4e67a7 100644
--- a/core/modules/simpletest/src/TestDiscovery.php
+++ b/core/modules/simpletest/src/TestDiscovery.php
@@ -177,7 +177,9 @@ public function getTestClasses($extension = NULL) {
     }
 
     // Sort the groups and tests within the groups by name.
-    uksort($list, 'strnatcasecmp');
+    // Use case-sensitive sorting for groups to make capitalized groups of core
+    // components appear first.
+    uksort($list, 'strnatcmp');
     foreach ($list as &$tests) {
       uksort($tests, 'strnatcasecmp');
     }
diff --git a/core/modules/system/src/Tests/Block/SystemMenuBlockTest.php b/core/modules/system/src/Tests/System/SystemMenuBlockTest.php
similarity index 98%
rename from core/modules/system/src/Tests/Block/SystemMenuBlockTest.php
rename to core/modules/system/src/Tests/System/SystemMenuBlockTest.php
index ce5b81b..fc64a02 100644
--- a/core/modules/system/src/Tests/Block/SystemMenuBlockTest.php
+++ b/core/modules/system/src/Tests/System/SystemMenuBlockTest.php
@@ -1,9 +1,11 @@
 <?php
+
 /**
- * Contains \Drupal\system\Tests\Block\SystemMenuBlockTest
+ * @file
+ * Contains \Drupal\system\Tests\System\SystemMenuBlockTest.
  */
 
-namespace Drupal\system\Tests\Block;
+namespace Drupal\system\Tests\System;
 
 use Drupal\Core\Render\Element;
 use Drupal\simpletest\KernelTestBase;
@@ -18,7 +20,7 @@
 /**
  * Tests \Drupal\system\Plugin\Block\SystemMenuBlock.
  *
- * @group Block
+ * @group system
  * @todo Expand test coverage to all SystemMenuBlock functionality, including
  *   block_menu_delete().
  *
diff --git a/core/profiles/testing/modules/drupal_system_listing_compatible_test/src/Tests/SystemListingCompatibleTest.php b/core/profiles/testing/modules/drupal_system_listing_compatible_test/src/Tests/SystemListingCompatibleTest.php
index 5fb0932..ca3a322 100644
--- a/core/profiles/testing/modules/drupal_system_listing_compatible_test/src/Tests/SystemListingCompatibleTest.php
+++ b/core/profiles/testing/modules/drupal_system_listing_compatible_test/src/Tests/SystemListingCompatibleTest.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Definition of Drupal\drupal_system_listing_compatible_test\Tests\SystemListingCompatibleTest.
+ * Contains \Drupal\drupal_system_listing_compatible_test\Tests\SystemListingCompatibleTest.
  */
 
 namespace Drupal\drupal_system_listing_compatible_test\Tests;
@@ -13,7 +13,7 @@
  * Verifies that tests in installation profile modules are found and may use
  * another profile for running tests.
  *
- * @group drupal_system_listing_compatible_test
+ * @group simpletest
  */
 class SystemListingCompatibleTest extends WebTestBase {
 
@@ -33,7 +33,7 @@ class SystemListingCompatibleTest extends WebTestBase {
    * This test needs to use a different installation profile than the test which
    * asserts that this test is found.
    *
-   * @see SimpleTestInstallationProfileModuleTestsTestCase
+   * @see \Drupal\simpletest\Tests\InstallationProfileModuleTestsTest
    */
   protected $profile = 'minimal';