diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
index cb0a53d5d6..8b21f6c644 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
@@ -56,6 +56,7 @@ use Symfony\Component\Validator\ConstraintValidatorInterface;
 use Symfony\Component\Validator\ObjectInitializerInterface;
 use Symfony\Component\WebLink\HttpHeaderSerializer;
 use Symfony\Component\Workflow;
+use Symfony\Component\Yaml\Yaml;
 
 /**
  * FrameworkExtension.
@@ -1172,6 +1173,10 @@ class FrameworkExtension extends Extension
             $container->removeDefinition('serializer.normalizer.object');
         }
 
+        if (!class_exists(Yaml::class)) {
+            $container->removeDefinition('serializer.encoder.yaml');
+        }
+
         $serializerLoaders = array();
         if (isset($config['enable_annotations']) && $config['enable_annotations']) {
             if (!$this->annotationsConfigEnabled) {