diff --git a/src/Entity/Form/Oauth2TokenSettingsForm.php b/src/Entity/Form/Oauth2TokenSettingsForm.php
index 4370c92..00d258f 100644
--- a/src/Entity/Form/Oauth2TokenSettingsForm.php
+++ b/src/Entity/Form/Oauth2TokenSettingsForm.php
@@ -7,7 +7,7 @@ use Drupal\Core\Form\ConfigFormBase;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Messenger\MessengerInterface;
 use Drupal\Core\Url;
-use Drupal\simple_oauth\Service\Filesystem\FilesystemInterface;
+use Drupal\simple_oauth\Service\Filesystem\FileSystemChecker;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
@@ -16,9 +16,9 @@ use Symfony\Component\DependencyInjection\ContainerInterface;
 class Oauth2TokenSettingsForm extends ConfigFormBase {
 
   /**
-   * @var \Drupal\simple_oauth\Service\Filesystem\FilesystemInterface
+   * @var \Drupal\simple_oauth\Service\Filesystem\FileSystemChecker
    */
-  protected $fileSystem;
+  protected $fileSystemChecker;
 
   /**
    * The messenger service.
@@ -33,14 +33,14 @@ class Oauth2TokenSettingsForm extends ConfigFormBase {
    *
    * @param \Drupal\Core\Config\ConfigFactoryInterface $configFactory
    *   The factory for configuration objects.
-   * @param \Drupal\simple_oauth\Service\Filesystem\FilesystemInterface $fileSystem
+   * @param \Drupal\simple_oauth\Service\Filesystem\FileSystemChecker $file_system_checker
    *   The simple_oauth.filesystem service.
    * @param \Drupal\Core\Messenger\MessengerInterface $messenger
    *   The messenger service.
    */
-  public function __construct(ConfigFactoryInterface $configFactory, FilesystemInterface $fileSystem, MessengerInterface $messenger) {
+  public function __construct(ConfigFactoryInterface $configFactory, FileSystemChecker $file_system_checker, MessengerInterface $messenger) {
     parent::__construct($configFactory);
-    $this->fileSystem = $fileSystem;
+    $this->fileSystemChecker = $file_system_checker;
     $this->messenger = $messenger;
   }
 
@@ -50,7 +50,7 @@ class Oauth2TokenSettingsForm extends ConfigFormBase {
   public static function create(ContainerInterface $container) {
     return new static(
       $container->get('config.factory'),
-      $container->get('simple_oauth.filesystem'),
+      $container->get('simple_oauth.filesystem_checker'),
       $container->get('messenger')
     );
   }
@@ -150,7 +150,7 @@ class Oauth2TokenSettingsForm extends ConfigFormBase {
     ];
 
     // Generate Key Modal Button if openssl extension is enabled.
-    if ($this->fileSystem->isExtensionEnabled('openssl')) {
+    if ($this->fileSystemChecker->isExtensionEnabled('openssl')) {
       // Generate Modal Button.
       $form['actions']['generate']['keys'] = [
         '#type' => 'link',
@@ -193,11 +193,11 @@ class Oauth2TokenSettingsForm extends ConfigFormBase {
     if (!empty($element['#value'])) {
       $path = $element['#value'];
       // Does the file exist?
-      if (!$this->fileSystem->fileExist($path)) {
+      if (!$this->fileSystemChecker->fileExist($path)) {
         $form_state->setError($element, $this->t('The %field file does not exist.', ['%field' => $element['#title']]));
       }
       // Is the file readable?
-      if (!$this->fileSystem->isReadable($path)) {
+      if (!$this->fileSystemChecker->isReadable($path)) {
         $form_state->setError($element, $this->t('The %field file at the specified location is not readable.', ['%field' => $element['#title']]));
       }
     }