Double check this to see if this helps. Robert Ramey Derived.cpp: #include "Derived.h" #include "boost/serialization/nvp.hpp" #include "boost/serialization/nvp.hpp" // make sure these are included BEFORE the EXPORT below. // code is intantiatiated only for archives already "seen" #include "boost/archive/polymorphic_iarchive.hpp" #include "boost/archive/polymorphic_oarchive.hpp" template<class Archive> void Derived::serialize(Archive& ar, const unsigned int version) { ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base); ar & BOOST_SERIALIZATION_NVP(j); } BOOST_CLASS_EXPORT_IMPLEMENT(Derived); template void __declspec(dllexport) Derived::serialize(boost::archive::polymorphic_iarchive& ar, const unsigned int version); template void __declspec(dllexport) Derived::serialize(boost::archive::polymorphic_oarchive& ar, const unsigned int version);