diff --git a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php
index fd6c2ccaf2..5168f74902 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php
@@ -18,6 +18,7 @@ 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
@@ -442,6 +443,17 @@ abstract class FrameworkExtensionTest extends TestCase
         $this->assertTrue($container->has('serializer'));
     }
 
+    public function testObjectNormalizerRegistered()
+    {
+        $container = $this->createContainerFromFile('full');
+
+        $definition = $container->getDefinition('serializer.normalizer.object');
+        $tag = $definition->getTag('serializer.normalizer');
+
+        $this->assertEquals(ObjectNormalizer::class, $definition->getClass());
+        $this->assertEquals(-1000, $tag[0]['priority']);
+    }
+
     public function testAssetHelperWhenAssetsAreEnabled()
     {
         $container = $this->createContainerFromFile('full');