I'm using protobuf-net version 2.0.0.668 (runtime version v2.0.50727) in a C# application using .NET 4.5

I tryed to run this code:

Person newPerson;
using (var file = File.OpenRead("person.bin")) {
    newPerson = Serializer.Deserialize<Person>(file);
}

But I get this error:

Error 3 The type 'System.Xml.XmlWriter' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Xml, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.

Even if I've already added System.Xml 4.0.0 in my referencies