diff --git a/core/modules/locale/locale.services.yml b/core/modules/locale/locale.services.yml
index 09dd9f5..1d55460 100644
--- a/core/modules/locale/locale.services.yml
+++ b/core/modules/locale/locale.services.yml
@@ -7,7 +7,7 @@ services:
     class: Drupal\locale\LocaleConfigManager
     arguments: ['@config.storage', '@locale.storage', '@config.factory', '@config.typed', '@language_manager', '@locale.default.config.storage']
     calls:
-      - [setConfigManager, ['@config.manager']]
+      - [_setConfigManager, ['@config.manager']]
   locale.storage:
     class: Drupal\locale\StringDatabaseStorage
     arguments: ['@database']
diff --git a/core/modules/locale/src/LocaleConfigManager.php b/core/modules/locale/src/LocaleConfigManager.php
index 56d70fc..c57e8cc 100644
--- a/core/modules/locale/src/LocaleConfigManager.php
+++ b/core/modules/locale/src/LocaleConfigManager.php
@@ -100,8 +100,11 @@ class LocaleConfigManager {
    * The configuration manager.
    *
    * @var \Drupal\Core\Config\ConfigManagerInterface
+   *
+   * @internal
+   *   Will be renamed to $configManager in 8.1.0.
    */
-  protected $configManager;
+  protected $_configManager;
 
   /**
    * Creates a new typed configuration manager.
@@ -136,8 +139,8 @@ public function __construct(StorageInterface $config_storage, StringStorageInter
    * @internal
    *   Will be replaced by constructor injection in 8.1.0.
    */
-  public function setConfigManager(ConfigManagerInterface $config_manager) {
-    $this->configManager = $config_manager;
+  public function _setConfigManager(ConfigManagerInterface $config_manager) {
+    $this->_configManager = $config_manager;
   }
 
   /**
@@ -149,11 +152,11 @@ public function setConfigManager(ConfigManagerInterface $config_manager) {
    * @internal
    *   Will be replaced by constructor injection in 8.1.0.
    */
-  protected function getConfigManager() {
-    if (isset($this->configManager)) {
-      return $this->configManager;
+  protected function _getConfigManager() {
+    if (!isset($this->_configManager)) {
+      $this->_configManager = \Drupal::service('config.manager');
     }
-    return \Drupal::service('config.manager');
+    return $this->_configManager;
   }
 
   /**
@@ -518,7 +521,7 @@ public function getDefaultConfigLangcode($name) {
     // configurable_language entities are a special case since they can be
     // translated regardless of whether they are shipped if they in the standard
     // language list.
-    $config_entity_type = $this->getConfigManager()->getEntityTypeIdByName($name);
+    $config_entity_type = $this->_getConfigManager()->getEntityTypeIdByName($name);
     if (!$config_entity_type || $config_entity_type === 'configurable_language'
       || !empty($this->configFactory->get($name)->get('_core.default_config_hash'))
     ) {