diff --git a/core/includes/config.inc b/core/includes/config.inc
index 00c7fa6..71f9f5a 100644
--- a/core/includes/config.inc
+++ b/core/includes/config.inc
@@ -4,6 +4,7 @@
 use Drupal\Core\Config\FileStorage;
 use Drupal\Core\Config\NullStorage;
 use Drupal\Core\Config\StorageInterface;
+use Drupal\Core\Language\Language;
 
 /**
  * @file
@@ -106,6 +107,21 @@ function config($name) {
 }
 
 /**
+ * Sets the language on the configuration object factory.
+ *
+ * @param Drupal\Core\Language\Language $language
+ *   The language that config objects should have injected in to them.
+ *
+ * @return Drupal\Core\Language\Language $language
+ *   The language object that was previously set in the config factory.
+ */
+function config_factory_set_language(Language $language) {
+  $current_language = drupal_container()->get('config.factory')->getLanguage();
+  drupal_container()->get('config.factory')->setLanguage($language);
+  return $current_language;
+}
+
+/**
  * Returns a list of differences between configuration storages.
  *
  * @param Drupal\Core\Config\StorageInterface $source_storage
@@ -257,11 +273,11 @@ function config_import_invoke_owner(array $config_changes, StorageInterface $sou
       // handle the configuration change.
       $handled_by_module = FALSE;
       if (module_exists($module) && module_hook($module, 'config_import_' . $op)) {
-        $old_config = new Config($name, $target_storage);
+        $old_config = new Config($name, $target_storage, language_default());
         $old_config->load();
 
         $data = $source_storage->read($name);
-        $new_config = new Config($name, $target_storage);
+        $new_config = new Config($name, $target_storage, language_default());
         if ($data !== FALSE) {
           $new_config->setData($data);
         }
diff --git a/core/lib/Drupal/Core/Config/Config.php b/core/lib/Drupal/Core/Config/Config.php
index 6fc2a87..899abf6 100644
--- a/core/lib/Drupal/Core/Config/Config.php
+++ b/core/lib/Drupal/Core/Config/Config.php
@@ -8,6 +8,7 @@
 namespace Drupal\Core\Config;
 
 use Drupal\Component\Utility\NestedArray;
+use Drupal\Core\Language\Language;
 use Symfony\Component\EventDispatcher\EventDispatcher;
 
 /**
@@ -65,6 +66,13 @@ class Config {
   protected $eventDispatcher;
 
   /**
+   * The Language object used to override configuration data.
+   *
+   * @var Drupal\Core\Language\Language
+   */
+  protected $language;
+
+  /**
    * Constructs a configuration object.
    *
    * @param string $name
@@ -72,12 +80,15 @@ class Config {
    * @param Drupal\Core\Config\StorageInterface $storage
    *   A storage controller object to use for reading and writing the
    *   configuration data.
+   * @param Drupal\Core\Language\Language $language
+   *   The Language object used to override configuration data.
    * @param Symfony\Component\EventDispatcher\EventDispatcher $event_dispatcher
    *   The event dispatcher used to notify subscribers.
    */
-  public function __construct($name, StorageInterface $storage, EventDispatcher $event_dispatcher = NULL) {
+  public function __construct($name, StorageInterface $storage, Language $language, EventDispatcher $event_dispatcher = NULL) {
     $this->name = $name;
     $this->storage = $storage;
+    $this->language = $language;
     $this->eventDispatcher = $event_dispatcher ? $event_dispatcher : drupal_container()->get('dispatcher');
   }
 
@@ -416,4 +427,14 @@ public function merge(array $data_to_merge) {
     $this->data = NestedArray::mergeDeepArray(array($this->data, $data_to_merge), TRUE);
     return $this;
   }
+
+  /**
+   * Returns the language object for this Config object.
+   *
+   * @return \Drupal\Core\Language\Language
+   */
+  public function getLanguage() {
+    return $this->language;
+  }
 }
+
diff --git a/core/lib/Drupal/Core/Config/ConfigFactory.php b/core/lib/Drupal/Core/Config/ConfigFactory.php
index ca36ce7..c86a58a 100644
--- a/core/lib/Drupal/Core/Config/ConfigFactory.php
+++ b/core/lib/Drupal/Core/Config/ConfigFactory.php
@@ -8,6 +8,7 @@
 namespace Drupal\Core\Config;
 
 use Symfony\Component\EventDispatcher\EventDispatcher;
+use Drupal\Core\Language\Language;
 
 /**
  * Defines the configuration object factory.
@@ -46,10 +47,15 @@ class ConfigFactory {
    *   configuration data.
    * @param Symfony\Component\EventDispatcher\EventDispatcher
    *   An event dispatcher instance to use for configuration events.
+   * @param Drupal\Core\Language\Language
+   *   A language object to inject in to configuration objects.
    */
-  public function __construct(StorageInterface $storage, EventDispatcher $event_dispatcher) {
+  public function __construct(StorageInterface $storage, EventDispatcher $event_dispatcher, Language $language = NULL) {
     $this->storage = $storage;
     $this->eventDispatcher = $event_dispatcher;
+    // @todo: always inject language, once we figure out how to handle language
+    // and the DIC in early bootstrap phases.
+    $this->language = isset($language) ? $language : language_default();
   }
 
   /**
@@ -82,8 +88,27 @@ public function get($name) {
     // @todo The decrease of CPU time is interesting, since that means that
     //   ContainerBuilder involves plenty of function calls (which are known to
     //   be slow in PHP).
-    $config = new Config($name, $this->storage, $this->eventDispatcher);
+    $config = new Config($name, $this->storage, $this->language, $this->eventDispatcher);
     return $config->init();
   }
 
+  /**
+   * Set the language to be injected in to Config objects.
+   *
+   * @param Language $language
+   * @return ConfigFactory
+   */
+  public function setLanguage(Language $language) {
+    $this->language = $language;
+    return $this;
+  }
+
+  /**
+   * Get the language to be injected in to Config objects.
+   *
+   * @return Drupal\Core\Language\Language
+   */
+  public function getLanguage() {
+    return $this->language;
+  }
 }
diff --git a/core/lib/Drupal/Core/EventSubscriber/PathSubscriber.php b/core/lib/Drupal/Core/EventSubscriber/PathSubscriber.php
index 8f0359d..26860e9 100644
--- a/core/lib/Drupal/Core/EventSubscriber/PathSubscriber.php
+++ b/core/lib/Drupal/Core/EventSubscriber/PathSubscriber.php
@@ -88,6 +88,15 @@ public function onKernelRequestLanguageResolve(GetResponseEvent $event) {
     //   prior to front page and alias resolution. When above is decoupled, also
     //   add 'langcode' (determined from $request only) to $request->attributes.
     drupal_language_initialize();
+
+    // Set the negotiated language as the default for Config objects created by
+    // the ConfigFactory.
+    $language = drupal_container()
+      ->get('language_manager')
+      ->getLanguage(LANGUAGE_TYPE_INTERFACE);
+    drupal_container()
+      ->get('config.factory')
+      ->setLanguage($language);
   }
 
   /**
diff --git a/core/modules/locale/lib/Drupal/locale/LocaleConfigSubscriber.php b/core/modules/locale/lib/Drupal/locale/LocaleConfigSubscriber.php
index 3d2fd4a..4ae656d 100644
--- a/core/modules/locale/lib/Drupal/locale/LocaleConfigSubscriber.php
+++ b/core/modules/locale/lib/Drupal/locale/LocaleConfigSubscriber.php
@@ -26,7 +26,7 @@ class LocaleConfigSubscriber implements EventSubscriberInterface {
    */
   public function configLoad(ConfigEvent $event) {
     $config = $event->getConfig();
-    $language = language(LANGUAGE_TYPE_INTERFACE);
+    $language = $config->getLanguage();
     $locale_name = $this->getLocaleConfigName($config->getName(), $language);
     if ($override = $config->getStorage()->read($locale_name)) {
       $config->setOverride($override);
diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index 285b9a7..59d9c67 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -1893,8 +1893,16 @@ function user_view_multiple($accounts, $view_mode = 'full', $langcode = NULL) {
 function user_mail($key, &$message, $params) {
   $langcode = $message['langcode'];
   $variables = array('user' => $params['account']);
+
+  // Make sure that we get configuration values for the user's language, not
+  // the site default language.
+  $config_language = config_factory_set_language(language_load(user_preferred_langcode($params['account'])));
+
   $message['subject'] .= _user_mail_text($key . '.subject', $langcode, $variables);
   $message['body'][] = _user_mail_text($key . '.body', $langcode, $variables);
+
+  // Set the language back to the site default.
+  config_factory_set_language($config_language);
 }
 
 /**