diff -u b/core/modules/system/system.install b/core/modules/system/system.install
--- b/core/modules/system/system.install
+++ b/core/modules/system/system.install
@@ -1933,6 +1933,14 @@
 }
 
 /**
+ * Remove the registry tables.
+ */
+function system_update_8014() {
+  db_drop_table('registry');
+  db_drop_table('registry_file');
+}
+
+/**
  * @} End of "defgroup updates-7.x-to-8.x".
  * The next series of updates should start at 9000.
  */
only in patch2:
unchanged:
--- a/core/modules/system/lib/Drupal/system/Tests/Upgrade/UpgradePathTestBase.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Upgrade/UpgradePathTestBase.php
@@ -110,11 +110,6 @@ abstract class UpgradePathTestBase extends WebTestBase {
       return FALSE;
     }
 
-    // Unregister the registry.
-    // This is required to make sure that the database layer works properly.
-    spl_autoload_unregister('drupal_autoload_class');
-    spl_autoload_unregister('drupal_autoload_interface');
-
     // Load the database from the portable PHP dump.
     // The files may be gzipped.
     foreach ($this->databaseDumpFiles as $file) {
@@ -258,10 +253,6 @@ abstract class UpgradePathTestBase extends WebTestBase {
       drupal_load('module', $module);
     }
 
-    // Re-register autoload functions.
-    spl_autoload_register('drupal_autoload_class');
-    spl_autoload_register('drupal_autoload_interface');
-
     // Reload hook implementations
     module_implements_reset();