diff --git a/src/Plugin/Validation/Constraint/SafeSearchConstraintValidator.php b/src/Plugin/Validation/Constraint/SafeSearchConstraintValidator.php
index 02e59d3..48543f8 100755
--- a/src/Plugin/Validation/Constraint/SafeSearchConstraintValidator.php
+++ b/src/Plugin/Validation/Constraint/SafeSearchConstraintValidator.php
@@ -11,6 +11,7 @@ use Drupal\file\FileInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
 use Drupal\google_vision\GoogleVisionAPI;
+use Drupal\Core\File\FileSystemInterface;
 
 /**
  * Validates the SafeSearch constraint.
@@ -22,16 +23,27 @@ class SafeSearchConstraintValidator extends ConstraintValidator implements Conta
    *
    * @var \Drupal\google_vision\GoogleVisionAPI.
    */
-  protected $googlevisionapi;
+  protected $googleVisionAPI;
+
+  /**
+   * The file system.
+   *
+   * @var \Drupal\Core\File\FileSystemInterface.
+   */
+  protected $fileSystem;
 
   /**
    * Constructs a SafeSearchConstraintValidator object.
    *
-   * @param \Drupal\google_vision\GoogleVisionAPI $googlevisionapi
-   *  The Google Vision APi object.
+   * @param \Drupal\google_vision\GoogleVisionAPI $googleVisionAPI
+   *  The Google Vision API object.
+   *
+   * @param \Drupal\Core\File\FileSystemInterface $fileSystem
+   *  The File System object.
    */
-  public function __construct(GoogleVisionAPI $google_vision) {
-    $this->googlevisionapi = $google_vision;
+  public function __construct(GoogleVisionAPI $google_vision, FileSystemInterface $file_system) {
+    $this->googleVisionAPI = $google_vision;
+    $this->fileSystem = $file_system;
   }
 
   /**
@@ -46,8 +58,8 @@ class SafeSearchConstraintValidator extends ConstraintValidator implements Conta
       if (!empty($data->getValue('target_id'))) {
         // Retrieve the file uri.
         $file_uri = $data->entity->getFileUri();
-        if ($filepath = \Drupal::service('file_system')->realpath($file_uri)) {
-          $result = $this->googlevisionapi->safeSearchDetection($filepath);
+        if ($filepath = $this->fileSystem->realpath($file_uri)) {
+          $result = $this->googleVisionAPI->safeSearchDetection($filepath);
           if (!empty($result['responses'][0]['safeSearchAnnotation'])) {
             $adult = $result['responses'][0]['safeSearchAnnotation']['adult'];
             $likelihood = array('LIKELY', 'VERY_LIKELY');
@@ -65,7 +77,9 @@ class SafeSearchConstraintValidator extends ConstraintValidator implements Conta
    * {@inheritdoc}
    */
   public static function create(ContainerInterface $container) {
-    return new static ($container->get('google_vision.api')
+    return new static (
+      $container->get('google_vision.api'),
+      $container->get('file_system')
     );
   }
 }