diff -u b/core/modules/system/src/Tests/Update/DbUpdatesTrait.php b/core/modules/system/src/Tests/Update/DbUpdatesTrait.php
--- b/core/modules/system/src/Tests/Update/DbUpdatesTrait.php
+++ b/core/modules/system/src/Tests/Update/DbUpdatesTrait.php
@@ -2,6 +2,8 @@
 
 namespace Drupal\system\Tests\Update;
 
+@trigger_error(__NAMESPACE__ . '\DbUpdatesTrait is deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0. Use \Drupal\FunctionalTests\Update\DbUpdatesTrait instead. See https://www.drupal.org/node/2896640.', E_USER_DEPRECATED);
+
 use Drupal\Core\StringTranslation\StringTranslationTrait;
 use Drupal\Core\Url;
 
@@ -13,6 +15,7 @@
  *
  * @deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0.
  *   Use \Drupal\FunctionalTests\Update\DbUpdatesTrait.
+ * @see https://www.drupal.org/node/2896640
  */
 trait DbUpdatesTrait {
 
diff -u b/core/modules/system/src/Tests/Update/UpdatePathTestBase.php b/core/modules/system/src/Tests/Update/UpdatePathTestBase.php
--- b/core/modules/system/src/Tests/Update/UpdatePathTestBase.php
+++ b/core/modules/system/src/Tests/Update/UpdatePathTestBase.php
@@ -2,6 +2,8 @@
 
 namespace Drupal\system\Tests\Update;
 
+@trigger_error(__NAMESPACE__ . '\UpdatePathTestBase is deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0. Use \Drupal\FunctionalTests\Update\UpdatePathTestBase instead. See https://www.drupal.org/node/2896640.', E_USER_DEPRECATED);
+
 use Drupal\Component\Utility\Crypt;
 use Drupal\Tests\SchemaCheckTestTrait;
 use Drupal\Core\Database\Database;
@@ -36,6 +38,7 @@
  *
  * @deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0.
  *   Use \Drupal\FunctionalTests\Update\UpdatePathTestBase.
+ * @see https://www.drupal.org/node/2896640
  *
  * @see hook_update_N()
  */
diff -u b/core/modules/system/tests/src/Functional/Update/DbUpdatesTrait.php b/core/modules/system/src/Tests/Update/DbUpdatesTrait.php
--- b/core/modules/system/tests/src/Functional/Update/DbUpdatesTrait.php
+++ b/core/modules/system/src/Tests/Update/DbUpdatesTrait.php
@@ -1,6 +1,8 @@
 <?php
 
-namespace Drupal\Tests\system\Functional\Update;
+namespace Drupal\system\Tests\Update;
+
+@trigger_error(__NAMESPACE__ . '\DbUpdatesTrait is deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0. Use \Drupal\FunctionalTests\Update\DbUpdatesTrait instead. See https://www.drupal.org/node/2896640.', E_USER_DEPRECATED);
 
 use Drupal\Core\StringTranslation\StringTranslationTrait;
 use Drupal\Core\Url;
@@ -9,7 +11,11 @@
  * Provides methods to conditionally enable db update functions and apply
  * pending db updates through the Update UI.
  *
- * This should be used only by classes extending \Drupal\Tests\BrowserTestBase.
+ * This should be used only by classes extending \Drupal\simpletest\WebTestBase.
+ *
+ * @deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0.
+ *   Use \Drupal\FunctionalTests\Update\DbUpdatesTrait.
+ * @see https://www.drupal.org/node/2896640
  */
 trait DbUpdatesTrait {
 
diff -u b/core/tests/Drupal/FunctionalTests/Update/UpdatePathTestBase.php b/core/tests/Drupal/FunctionalTests/Update/UpdatePathTestBase.php
--- b/core/tests/Drupal/FunctionalTests/Update/UpdatePathTestBase.php
+++ b/core/tests/Drupal/FunctionalTests/Update/UpdatePathTestBase.php
@@ -187,9 +187,6 @@
     // Add the config directories to settings.php.
     drupal_install_config_directories();
 
-    // Restore the original Simpletest batch.
-    // $this->restoreBatch();
-
     // Set the container. parent::rebuildAll() would normally do this, but this
     // not safe to do here, because the database has not been updated yet.
     $this->container = \Drupal::getContainer();