diff --git a/core/includes/update.inc b/core/includes/update.inc
index 70edeaf..0869f1f 100644
--- a/core/includes/update.inc
+++ b/core/includes/update.inc
@@ -219,6 +219,48 @@ function update_do_one($module, $number, $dependency_map, &$context) {
 }
 
 /**
+ * Executes a single hook_update_after_$name().
+ */
+function update_after_do_one($function, &$context) {
+  $ret = [];
+  list($module, ) = explode('_update_after_', $function);
+  module_load_include('inc', $module, $module . '.update_after');
+  if (function_exists($function)) {
+    try {
+      $ret['results']['query'] = $function($context['sandbox']);
+      $ret['results']['success'] = TRUE;
+    }
+      // @TODO We may want to do different error handling for different
+      // exception types, but for now we'll just log the exception and
+      // return the message for printing.
+    catch (Exception $e) {
+      watchdog_exception('update', $e);
+
+      $variables = Error::decodeException($e);
+      unset($variables['backtrace']);
+      $ret['#abort'] = [
+        'success' => FALSE,
+        'query' => t('%type: @message in %function (line %line of %file).', $variables)
+      ];
+    }
+  }
+
+  if (isset($context['sandbox']['#finished'])) {
+    $context['finished'] = $context['sandbox']['#finished'];
+    unset($context['sandbox']['#finished']);
+  }
+
+  $context['results'][$function] = $ret;
+
+  if (!empty($ret['#abort'])) {
+    // Record this function in the list of updates that were aborted.
+    $context['results']['#abort'][] = $function;
+  }
+
+  $context['message'] = 'Updating content after: ' . Html::escape($function);
+}
+
+/**
  * Returns a list of all the pending database updates.
  *
  * @return
diff --git a/core/lib/Drupal/Core/Extension/ExtensionDiscovery.php b/core/lib/Drupal/Core/Extension/ExtensionDiscovery.php
index 98067f6..5ce0f7b 100644
--- a/core/lib/Drupal/Core/Extension/ExtensionDiscovery.php
+++ b/core/lib/Drupal/Core/Extension/ExtensionDiscovery.php
@@ -95,6 +95,12 @@ class ExtensionDiscovery {
    *
    * @param string $root
    *   The app root.
+   * @param bool $use_file_cache
+   *   Whether file cache should be used.
+   * @param string[] $profile_directories
+   *   The available profile directories
+   * @param string $site_path
+   *   The path to the site.
    */
   public function __construct($root, $use_file_cache = TRUE, $profile_directories = NULL, $site_path = NULL) {
     $this->root = $root;
diff --git a/core/lib/Drupal/Core/Update/UpdateRegistry.php b/core/lib/Drupal/Core/Update/UpdateRegistry.php
index 0a7e90d..cf4bcc9 100644
--- a/core/lib/Drupal/Core/Update/UpdateRegistry.php
+++ b/core/lib/Drupal/Core/Update/UpdateRegistry.php
@@ -16,7 +16,7 @@
  */
 class UpdateRegistry {
 
-  protected $updateName = 'update_data';
+  protected $updateName = 'update_after';
 
   /**
    * The app root.
@@ -44,11 +44,19 @@ class UpdateRegistry {
    */
   protected $keyValue;
 
-  public function __construct($root, $site_path, array $enabled_modules, KeyValueStoreInterface $key_value) {
+  /**
+   * Should we respect update functions in tests.
+   *
+   * @var bool|null
+   */
+  protected $includeTests = NULL;
+
+  public function __construct($root, $site_path, array $enabled_modules, KeyValueStoreInterface $key_value, $include_tests = NULL) {
     $this->root = $root;
     $this->sitePath = $site_path;
     $this->enabledModules = $enabled_modules;
     $this->keyValue = $key_value;
+    $this->includeTests = $include_tests;
   }
 
   /**
@@ -85,7 +93,7 @@ public function getMissingUpdateFunctions() {
     // Scan the module list.
     // We don't support install profiles at that point?
     $extension_discovery = new ExtensionDiscovery($this->root, FALSE, [], $this->sitePath);
-    $module_extensions = $extension_discovery->scan('module', FALSE);
+    $module_extensions = $extension_discovery->scan('module');
 
     $this->loadUpdateFiles($module_extensions);
 
@@ -102,7 +110,7 @@ protected function loadUpdateFiles(array $module_extensions) {
     // Load all the {$this->updateName}.inc files.
     foreach ($this->enabledModules as $module) {
       if (isset($module_extensions[$module])) {
-        $this->loadUpdateEarlyFile($module_extensions[$module]);
+        $this->loadUpdateFile($module_extensions[$module]);
       }
     }
   }
@@ -112,7 +120,7 @@ protected function loadUpdateFiles(array $module_extensions) {
    *
    * @param \Drupal\Core\Extension\Extension $module
    */
-  protected function loadUpdateEarlyFile(Extension $module) {
+  protected function loadUpdateFile(Extension $module) {
     $filename = $this->root . '/' . $module->getPath() . '/' . $module->getName() . ".{$this->updateName}.inc";
     if (file_exists($filename)) {
       include_once $filename;
diff --git a/core/modules/system/src/Controller/DbUpdateController.php b/core/modules/system/src/Controller/DbUpdateController.php
index fa8104d..fce7819 100644
--- a/core/modules/system/src/Controller/DbUpdateController.php
+++ b/core/modules/system/src/Controller/DbUpdateController.php
@@ -15,6 +15,7 @@
 use Drupal\Core\Session\AccountInterface;
 use Drupal\Core\Site\Settings;
 use Drupal\Core\State\StateInterface;
+use Drupal\Core\Update\UpdateRegistry;
 use Drupal\Core\Url;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\Response;
@@ -575,6 +576,17 @@ protected function triggerBatch(Request $request) {
       }
     }
 
+    // Now we rebuild all caches and after that execute the hook_update_after()
+    // functions.
+    $operations[] = ['drupal_flush_all_caches', []];
+
+    $after_update_registry = $this->getUpdateAfterRegistry();
+    $after_updates = $after_update_registry->getMissingUpdateFunctions();
+
+    foreach ($after_updates as $function) {
+      $operations[] = ['update_after_do_one', [$function]];
+    }
+
     $batch['operations'] = $operations;
     $batch += array(
       'title' => $this->t('Updating'),
@@ -588,6 +600,10 @@ protected function triggerBatch(Request $request) {
     return batch_process(Url::fromUri('base://results'), Url::fromUri('base://start'));
   }
 
+  protected function getUpdateAfterRegistry() {
+    return new UpdateRegistry($this->root, \Drupal::service('site.path'), array_keys($this->moduleHandler()->getModuleList()), \Drupal::keyValue('update_after'));
+  }
+
   /**
    * Finishes the update process and stores the results for eventual display.
    *
diff --git a/core/modules/system/src/Tests/Update/UpdateAfterTest.php b/core/modules/system/src/Tests/Update/UpdateAfterTest.php
index 1cab15d..0b85fcb 100644
--- a/core/modules/system/src/Tests/Update/UpdateAfterTest.php
+++ b/core/modules/system/src/Tests/Update/UpdateAfterTest.php
@@ -24,4 +24,15 @@ protected function setDatabaseDumpFiles() {
     ];
   }
 
+  public function testUpdateAfter() {
+    $this->runUpdates();
+
+    $this->assertIdentical([
+      'update_test_after_update_after_first',
+      'update_test_after_update_after_second',
+      'update_test_after_update_after_test1',
+      'update_test_after_update_after_test0',
+    ], \Drupal::state()->get('update_test_after_execution', []));
+  }
+
 }
diff --git a/core/modules/system/tests/fixtures/update/drupal-8.update-test-after-enabled.php b/core/modules/system/tests/fixtures/update/drupal-8.update-test-after-enabled.php
index a4abe2d..681a5fb 100644
--- a/core/modules/system/tests/fixtures/update/drupal-8.update-test-after-enabled.php
+++ b/core/modules/system/tests/fixtures/update/drupal-8.update-test-after-enabled.php
@@ -1,2 +1,39 @@
 <?php
 
+/**
+ * @file
+ * Partial database to mimic the installation of the update_test_after module.
+ */
+
+use Drupal\Core\Database\Database;
+
+$connection = Database::getConnection();
+
+// Set the schema version.
+$connection->merge('key_value')
+  ->condition('collection', 'system.schema')
+  ->condition('name', 'update_test_schema')
+  ->fields([
+    'collection' => 'system.schema',
+    'name' => 'update_test_after',
+    'value' => 'i:8000;',
+  ])
+  ->execute();
+
+// Update core.extension.
+$extensions = $connection->select('config')
+  ->fields('config', ['data'])
+  ->condition('collection', '')
+  ->condition('name', 'core.extension')
+  ->execute()
+  ->fetchField();
+$extensions = unserialize($extensions);
+$extensions['module']['update_test_after'] = 8000;
+$connection->update('config')
+  ->fields([
+    'data' => serialize($extensions),
+  ])
+  ->condition('collection', '')
+  ->condition('name', 'core.extension')
+  ->execute();
+
diff --git a/core/tests/Drupal/Tests/Core/Update/UpdateRegistryTest.php b/core/tests/Drupal/Tests/Core/Update/UpdateRegistryTest.php
index 0fb1ae9..b4cd0b5 100644
--- a/core/tests/Drupal/Tests/Core/Update/UpdateRegistryTest.php
+++ b/core/tests/Drupal/Tests/Core/Update/UpdateRegistryTest.php
@@ -37,17 +37,17 @@ protected function setupBasicModules($directories) {
     $module_a = <<<'EOS'
 <?php
 
-function module_a_update_data_a() {
+function module_a_update_after_a() {
 }
 
-function module_a_update_data_b() {
+function module_a_update_after_b() {
 }
 
 EOS;
     $module_b = <<<'EOS'
 <?php
 
-function module_b_update_data_a() {
+function module_b_update_after_a() {
 }
 
 EOS;
@@ -57,11 +57,11 @@ function module_b_update_data_a() {
         'default' => [
           'modules' => [
             'module_a' => [
-              'module_a.update_data.inc' => $module_a,
+              'module_a.update_after.inc' => $module_a,
               'module_a.info.yml' => $info_a
             ],
             'module_b' => [
-              'module_b.update_data.inc' => $module_b,
+              'module_b.update_after.inc' => $module_b,
               'module_b.info.yml' => $info_b
             ],
           ]
@@ -77,18 +77,18 @@ public function testGetMissingUpdateFunctionsWithNoExistingUpdates() {
     $this->setupBasicModules([]);
 
     $key_value = $this->prophesize(KeyValueStoreInterface::class);
-    $key_value->get('core.update__update_data', [])->wilLReturn([]);
+    $key_value->get('core.update__update_after', [])->wilLReturn([]);
     $key_value = $key_value->reveal();
 
     $update_registry = new UpdateRegistry('vfs://drupal', 'sites/default', [
       'module_a',
       'module_b'
-    ], $key_value);
+    ], $key_value, FALSE);
 
     $this->assertEquals([
-      'module_a_update_data_a',
-      'module_a_update_data_b',
-      'module_b_update_data_a'
+      'module_a_update_after_a',
+      'module_a_update_after_b',
+      'module_b_update_after_a'
     ], $update_registry->getMissingUpdateFunctions());
   }
 
@@ -99,17 +99,17 @@ public function testGetMissingUpdateFunctionsWithExistingUpdates() {
     $this->setupBasicModules([]);
 
     $key_value = $this->prophesize(KeyValueStoreInterface::class);
-    $key_value->get('core.update__update_data', [])->wilLReturn(['module_a_update_data_a']);
+    $key_value->get('core.update__update_after', [])->wilLReturn(['module_a_update_after_a']);
     $key_value = $key_value->reveal();
 
     $update_registry = new UpdateRegistry('vfs://drupal', 'sites/default', [
       'module_a',
       'module_b'
-    ], $key_value);
+    ], $key_value, FALSE);
 
     $this->assertEquals(array_values([
-      'module_a_update_data_b',
-      'module_b_update_data_a'
+      'module_a_update_after_b',
+      'module_b_update_after_a'
     ]), array_values($update_registry->getMissingUpdateFunctions()));
   }