diff --git a/core/modules/language/language.module b/core/modules/language/language.module
index 3cb07b3..c67407c 100644
--- a/core/modules/language/language.module
+++ b/core/modules/language/language.module
@@ -432,8 +432,6 @@ function language_save($language) {
   $language_entity->locked = !empty($language->locked);
   $language_entity->weight = isset($language->weight) ? $language->weight : 0;
 
-  // Save the record and inform others about the change.
-  $multilingual = \Drupal::languageManager()->isMultilingual();
   $language_entity->save();
   $t_args = array('%language' => $language->name, '%langcode' => $language->id);
   if ($language->is_new) {
@@ -443,30 +441,6 @@ function language_save($language) {
     watchdog('language', 'The %language (%langcode) language has been updated.', $t_args);
   }
 
-  if (!empty($language->default)) {
-    // Update the config. Saving the configuration fires and event that causes
-    // the container to be rebuilt.
-    \Drupal::config('system.site')->set('langcode', $language->id)->save();
-    \Drupal::service('language.default')->set($language);
-  }
-
-  $language_manager = \Drupal::languageManager();
-  $language_manager->reset();
-  if ($language_manager instanceof ConfigurableLanguageManagerInterface) {
-    $language_manager->updateLockedLanguageWeights();
-  }
-
-  // Update URL Prefixes for all languages after the new default language is
-  // propagated and the LanguageManagerInterface::getLanguages() cache is
-  // flushed.
-  language_negotiation_url_prefixes_update();
-
-  // If after adding this language the site will become multilingual, we need to
-  // rebuild language services.
-  if (!$multilingual && $language->is_new) {
-    ConfigurableLanguageManager::rebuildServices();
-  }
-
   return $language;
 }
 
diff --git a/core/modules/language/lib/Drupal/language/Entity/Language.php b/core/modules/language/lib/Drupal/language/Entity/Language.php
index 77015cd..3b079dd 100644
--- a/core/modules/language/lib/Drupal/language/Entity/Language.php
+++ b/core/modules/language/lib/Drupal/language/Entity/Language.php
@@ -90,6 +90,40 @@ public function preSave(EntityStorageInterface $storage) {
 
   /**
    * {@inheritdoc}
+   */
+  public function postSave(EntityStorageInterface $storage, $update = TRUE) {
+    parent::postSave($storage, $update);
+
+    // Save the record and inform others about the change.
+    $multilingual = \Drupal::languageManager()->isMultilingual();
+
+    if (!empty($this->default)) {
+      // Update the config. Saving the configuration fires and event that causes
+      // the container to be rebuilt.
+      \Drupal::config('system.site')->set('langcode', $this->id())->save();
+      \Drupal::service('language.default')->set($this);
+    }
+
+    $language_manager = \Drupal::languageManager();
+    $language_manager->reset();
+    if ($language_manager instanceof ConfigurableLanguageManagerInterface) {
+      $language_manager->updateLockedLanguageWeights();
+    }
+
+    // Update URL Prefixes for all languages after the new default language is
+    // propagated and the LanguageManagerInterface::getLanguages() cache is
+    // flushed.
+    language_negotiation_url_prefixes_update();
+
+    // If after adding this language the site will become multilingual, we need to
+    // rebuild language services.
+    if (!$multilingual && $this->isNew()) {
+      ConfigurableLanguageManager::rebuildServices();
+    }
+  }
+
+  /**
+   * {@inheritdoc}
    *
    * @throws \RuntimeException
    */