diff --git a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php
index 5168f74902..3c1a233514 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php
@@ -18,7 +18,6 @@ use Symfony\Component\DependencyInjection\DefinitionDecorator;
 use Symfony\Component\DependencyInjection\Loader\ClosureLoader;
 use Symfony\Component\DependencyInjection\ParameterBag\ParameterBag;
 use Symfony\Component\DependencyInjection\Reference;
-use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
 use Symfony\Component\Validator\Validation;
 
 abstract class FrameworkExtensionTest extends TestCase
@@ -450,7 +449,7 @@ abstract class FrameworkExtensionTest extends TestCase
         $definition = $container->getDefinition('serializer.normalizer.object');
         $tag = $definition->getTag('serializer.normalizer');
 
-        $this->assertEquals(ObjectNormalizer::class, $definition->getClass());
+        $this->assertEquals('Symfony\Component\Serializer\Normalizer\ObjectNormalizer', $definition->getClass());
         $this->assertEquals(-1000, $tag[0]['priority']);
     }