diff --git a/src/JsonapiServiceProvider.php b/src/JsonapiServiceProvider.php
index cfc5bba..7ff65c7 100644
--- a/src/JsonapiServiceProvider.php
+++ b/src/JsonapiServiceProvider.php
@@ -49,7 +49,6 @@ class JsonapiServiceProvider implements ServiceModifierInterface, ServiceProvide
         new Reference('jsonapi.link_manager'),
         new Reference('jsonapi.resource_type.repository'),
         new Reference('entity_type.manager'),
-        new Reference('file.mime_type.guesser'),
         new Reference('file_system'),
         new Reference('current_user'),
         new Reference('config.factory'),
diff --git a/src/Normalizer/FileEntityNormalizer.php b/src/Normalizer/FileEntityNormalizer.php
index d2b2f78..eb88ebf 100644
--- a/src/Normalizer/FileEntityNormalizer.php
+++ b/src/Normalizer/FileEntityNormalizer.php
@@ -12,7 +12,6 @@ use Drupal\file_entity\UploadValidatorsTrait;
 use Drupal\jsonapi\LinkManager\LinkManager;
 use Drupal\jsonapi\ResourceType\ResourceTypeRepository;
 use Drupal\user\Entity\User;
-use Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesserInterface;
 use Symfony\Component\HttpKernel\Exception\PreconditionFailedHttpException;
 use Symfony\Component\HttpKernel\Exception\PreconditionRequiredHttpException;
 
@@ -29,13 +28,6 @@ class FileEntityNormalizer extends EntityNormalizer {
   protected $supportedInterfaceOrClass = FileInterface::class;
 
   /**
-   * Mime type guesser service.
-   *
-   * @var \Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesserInterface
-   */
-  protected $mimeTypeGuesser;
-
-  /**
    * File System service.
    *
    * @var \Drupal\Core\File\FileSystemInterface
@@ -65,8 +57,6 @@ class FileEntityNormalizer extends EntityNormalizer {
    *   The JSON API resource type repository.
    * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
    *   The entity type manager.
-   * @param \Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesserInterface $mime_type_guesser
-   *   Mime type gusser service.
    * @param \Drupal\Core\File\FileSystemInterface $file_system
    *   File system service.
    * @param \Drupal\Core\Session\AccountInterface $current_user
@@ -74,9 +64,8 @@ class FileEntityNormalizer extends EntityNormalizer {
    * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   Site configs service.
    */
-  public function __construct(LinkManager $link_manager, ResourceTypeRepository $resource_type_repository, EntityTypeManagerInterface $entity_type_manager, MimeTypeGuesserInterface $mime_type_guesser, FileSystemInterface $file_system, AccountInterface $current_user, ConfigFactoryInterface $config_factory) {
+  public function __construct(LinkManager $link_manager, ResourceTypeRepository $resource_type_repository, EntityTypeManagerInterface $entity_type_manager, FileSystemInterface $file_system, AccountInterface $current_user, ConfigFactoryInterface $config_factory) {
     parent::__construct($link_manager, $resource_type_repository, $entity_type_manager);
-    $this->mimeTypeGuesser = $mime_type_guesser;
     $this->fileSystem = $file_system;
     $this->currentUser = $current_user;
     $this->configFactory = $config_factory;
@@ -109,10 +98,6 @@ class FileEntityNormalizer extends EntityNormalizer {
     // during the validation.
     $file->setSize(Unicode::strlen($file_contents));
 
-    // Set the correct file mime type.
-    $mime_type = $this->mimeTypeGuesser->guess($file->getFilename());
-    $file->setMimeType($mime_type);
-
     // Set the current user as the file owner.
     $account = User::load($this->currentUser->id());
     $file->setOwner($account);