diff --git a/core/core.services.yml b/core/core.services.yml
index 10dd0431d1..20e5da30d8 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -321,8 +321,6 @@ services:
   config.storage.staging:
     class: Drupal\Core\Config\FileStorage
     factory: Drupal\Core\Config\FileStorageFactory::getSync
-    calls:
-      - [setFileSystem, ['@file_system']]
   config.storage.sync:
     alias: config.storage.staging
   config.storage.snapshot:
diff --git a/core/lib/Drupal/Core/Config/FileStorage.php b/core/lib/Drupal/Core/Config/FileStorage.php
index 3c0d55075b..a2cd36e298 100644
--- a/core/lib/Drupal/Core/Config/FileStorage.php
+++ b/core/lib/Drupal/Core/Config/FileStorage.php
@@ -38,7 +38,7 @@ class FileStorage implements StorageInterface {
    *
    * @var \Drupal\Core\File\FileSystemInterface
    */
-  protected $fileSystem;
+  private $fileSystem;
 
   /**
    * Constructs a new FileStorage.
@@ -365,23 +365,13 @@ protected function getCollectionDirectory() {
     return $dir;
   }
 
-  /**
-   * Set the file system service.
-   *
-   * @param \Drupal\Core\File\FileSystemInterface $file_system
-   *   The file system service.
-   */
-  public function setFileSystem(FileSystemInterface $file_system) {
-    $this->fileSystem = $file_system;
-  }
-
   /**
    * Returns file system service.
    *
    * @return \Drupal\Core\File\FileSystemInterface
    *   The file system service.
    */
-  protected function getFileSystem() {
+  private function getFileSystem() {
     if (!isset($this->fileSystem)) {
       $this->fileSystem = \Drupal::service('file_system');
     }