It seems that the "using namespace ." statements in this and shared_count_132.hpp trigger a problem in VC8 + SP1. Try the following small program: #include <boost/serialization/shared_ptr_132.hpp> #include <boost/cstdint.hpp> typedef unsigned short uint16_t; int main(int argc, char* argv[]) { uint16_t u; return 0; } Will result in this error: error C2872: 'uint16_t' : ambiguous symbol It seems that the workaround implemented for Borland applies to VC8 too: #if !BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT( 0x560) ) using namespace boost; #endif Regards, Sean