I've been pulling my hair out for a couple of days trying to get this to work. When I serialize something from a base pointer, it throws an "unregistered_class" exception. I know the type of object that's being serialized and that class has "BOOST_CLASS_EXPORT_KEY" in the header and "BOOST_CLASS_EXPORT_IMPLEMENT" in the cpp file with the same name. In the save and load functions I also have: boost::serialization::void_cast_register( static_cast<Derived*>(NULL), static_cast<Base*>(NULL)); The base class is an abstract base class with one pure virtual function method. But here are the differences: 1) I tried using the "ASSUME_ABSTRACT....." macro. That didn't do anything for me. 2) The abstract base class also has a cpp file with some code in it. I'm not sure if that matters or not... Here's the thing. I can get the derived class's "save" method to be called with this code: std::ofstream o(case_path_ + "/" + file_name); if (o.good()) { // MUST HAVE THIS boost::serialization::void_cast_register<Derived, Base>( static_cast<Derived*>(NULL), static_cast<Base*>(NULL)); boost::archive::polymorphic_text_oarchive oa(o); boost::archive::polymorphic_oarchive & oa_interface = oa; oa_interface << base_ptr; } Having the void_cast_register() there sort of defeats the purpose though. I shouldn't need to pre-register them. In all the examples, I see the void_cast_register() inside of the "save" and "load" methods, which is what I have already. All my serialization code resides in cpp files. Also, the serialization code resides in a static lib. But the archive creation and the action to serialize is performed in a dynamic lib. I am also using polymorphic archives everywhere. I've also forced template instantiation of all serialization code and polymorphic archive interface stuff. Any clue?