diff --git a/core/lib/Drupal/Core/DrupalKernel.php b/core/lib/Drupal/Core/DrupalKernel.php
index 632c1c3..6495229 100644
--- a/core/lib/Drupal/Core/DrupalKernel.php
+++ b/core/lib/Drupal/Core/DrupalKernel.php
@@ -461,7 +461,7 @@ public function preHandle(Request $request) {
     UrlHelper::setAllowedProtocols($allowed_protocols);
 
     // Override of Symfony's mime type guesser singleton.
-    MimeTypeGuesser::overrideSymfonyGuessers();
+    MimeTypeGuesser::registerWithSymfonyGuesser($this->container);
   }
 
   /**
diff --git a/core/lib/Drupal/Core/File/MimeType/MimeTypeGuesser.php b/core/lib/Drupal/Core/File/MimeType/MimeTypeGuesser.php
index 6e31c73..2054463 100644
--- a/core/lib/Drupal/Core/File/MimeType/MimeTypeGuesser.php
+++ b/core/lib/Drupal/Core/File/MimeType/MimeTypeGuesser.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\Core\File\MimeType;
 
+use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesser as SymfonyMimeTypeGuesser;
 use Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesserInterface;
 
@@ -90,7 +91,7 @@ protected function sortGuessers() {
   }
 
   /**
-   * A helper function to override Symfony's default guessers.
+   * A helper function to register with Symfony's singleton mime type guesser.
    *
    * Symfony's default mimetype guessers have dependencies on PHP's fileinfo
    * extension or being able to run the system command file. Drupal's guesser
@@ -98,9 +99,9 @@ protected function sortGuessers() {
    *
    * @see \Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesser
    */
-  public static function overrideSymfonyGuessers() {
+  public static function registerWithSymfonyGuesser(ContainerInterface $container) {
     $singleton = SymfonyMimeTypeGuesser::getInstance();
-    $singleton->register(\Drupal::service('file.mime_type.guesser'));
+    $singleton->register($container->get('file.mime_type.guesser'));
   }
 
 }
diff --git a/core/tests/Drupal/Tests/Core/DrupalKernel/MimeTypeGuesserOverrideTest.php b/core/tests/Drupal/Tests/Core/File/MimeTypeGuesserTest.php
similarity index 61%
rename from core/tests/Drupal/Tests/Core/DrupalKernel/MimeTypeGuesserOverrideTest.php
rename to core/tests/Drupal/Tests/Core/File/MimeTypeGuesserTest.php
index ee24994..a1bf9c2 100644
--- a/core/tests/Drupal/Tests/Core/DrupalKernel/MimeTypeGuesserOverrideTest.php
+++ b/core/tests/Drupal/Tests/Core/File/MimeTypeGuesserTest.php
@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\Tests\Core\DrupalKernel\MimeTypeGuesserOverrideTest.
+ * Contains \Drupal\Tests\Core\File\MimeTypeGuesserTest.
  */
 
-namespace Drupal\Tests\Core\DrupalKernel;
+namespace Drupal\Tests\Core\File;
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Core\File\MimeType\MimeTypeGuesser;
@@ -16,39 +16,27 @@
  * @coversDefaultClass \Drupal\Core\File\MimeType\MimeTypeGuesser
  * @group DrupalKernel
  */
-class MimeTypeGuesserOverrideTest extends UnitTestCase {
+class MimeTypeGuesserTest extends UnitTestCase {
 
   /**
-   * {@inheritdoc}
-   */
-  protected function setUp() {
-    parent::setUp();
-    $container = new ContainerBuilder();
-    $container->set('file.mime_type.guesser', new MimeTypeGuesser());
-    \Drupal::setContainer($container);
-  }
-
-  /**
-   * @covers ::overrideSymfonyGuessers
+   * @covers ::registerWithSymfonyGuesser
    *
    * @see Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesser
    */
-  public function testSymfonyGuesserOverrider() {
+  public function testSymfonyGuesserRegistration() {
     // Make the guessers property accessible on Symfony's MimeTypeGuesser.
     $symfony_guesser = SymfonyMimeTypeGuesser::getInstance();
-    $reflection = new \ReflectionClass($symfony_guesser);
-    $property = $reflection->getProperty('guessers');
-    $property->setAccessible(TRUE);
-
     // Test that the Drupal mime type guess is not being used before the
     // override method is called. It is possible that the test environment does
     // not support the default guessers.
-    $guessers = $property->getValue($symfony_guesser);
+    $guessers = $this->readAttribute($symfony_guesser, 'guessers');
     if (count($guessers)) {
       $this->assertNotInstanceOf('Drupal\Core\File\MimeType\MimeTypeGuesser', $guessers[0]);
     }
-    MimeTypeGuesser::overrideSymfonyGuessers();
-    $guessers = $property->getValue($symfony_guesser);
+    $container = new ContainerBuilder();
+    $container->set('file.mime_type.guesser', new MimeTypeGuesser());
+    MimeTypeGuesser::registerWithSymfonyGuesser($container);
+    $guessers = $this->readAttribute($symfony_guesser, 'guessers');
     $this->assertInstanceOf('Drupal\Core\File\MimeType\MimeTypeGuesser', $guessers[0]);
   }