Fix not precise enough sentence

Nek- · Nek- · commit db38bad88222 · 2018-06-04T19:23:08.000+02:00
diff --git a/components/serializer.rst b/components/serializer.rst
@@ -1093,8 +1093,9 @@ Handling Constructor Arguments
 ------------------------------
 
 If the constructor of a class defines arguments, as usually happens with
-`Value Objects`_, the serializer won't be able to create the object. In those
-cases, use the ``default_constructor_arguments`` context option::
+`Value Objects`_, the serializer won't be able to create the object if some
+arguments are missing. In those cases, use the ``default_constructor_arguments``
+context option::
 
     use Symfony\Component\Serializer\Serializer;
     use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
