diff --git a/core/modules/rest/src/Plugin/rest/resource/UserRegistrationResource.php b/core/modules/rest/src/Plugin/rest/resource/UserRegistrationResource.php
index 30e1265..c0f97e2 100644
--- a/core/modules/rest/src/Plugin/rest/resource/UserRegistrationResource.php
+++ b/core/modules/rest/src/Plugin/rest/resource/UserRegistrationResource.php
@@ -10,6 +10,7 @@
 use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Entity\ContentEntityBase;
+use Drupal\Core\Render\RenderContext;
 use Drupal\rest\ResourceResponse;
 use Drupal\user\Entity\User;
 use Psr\Log\LoggerInterface;
@@ -128,18 +129,27 @@ public function post(User $account = NULL) {
     }
 
     $account->save();
+    // Send emails from a render context to add bubbleable_metadata to the response.
+    $context = new RenderContext();
+    $renderer = \Drupal::service('renderer');
+    $renderer->executeInRenderContext($context, function() use ($account) {
+      // "Verify email" option disabled and the account as active means that the user can be logged in now.
+      if (!$this->configFactory->get('user.settings')->get('verify_mail') && $account->isActive()) {
+        _user_mail_notify('register_no_approval_required', $account);
+        user_login_finalize($account);
+      }
+      // The new account as blocked means that it needs approval.
+      elseif (!$account->isActive()) {
+        _user_mail_notify('register_pending_approval', $account);
+      }
+    });
 
-    // "Verify email" option disabled and the account as active means that the user can be logged in now.
-    if (!$this->configFactory->get('user.settings')->get('verify_mail') && $account->isActive()) {
-      _user_mail_notify('register_no_approval_required', $account);
-      user_login_finalize($account);
-    }
-    // The new account as blocked means that it needs approval.
-    elseif (!$account->isActive()) {
-      _user_mail_notify('register_pending_approval', $account);
+    $response = new ResourceResponse(NULL, 201);
+    if (!$context->isEmpty()) {
+      $response->addCacheableDependency($context->pop());
     }
 
-    return new ResourceResponse(NULL, 201);
+    return $response;
   }
 
   /**
diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index 4b4bd6f..422d0bf 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -1207,7 +1207,7 @@ function user_role_revoke_permissions($rid, array $permissions = array()) {
  *   language.
  *
  * @return array
- *   An array containint various information about the message.
+ *   An array containing various information about the message.
  *   See \Drupal\Core\Mail\MailManagerInterface::mail() for details.
  *
  * @see user_mail_tokens()