The declaration BOOST_PYTHON_DECL void throw_error_already_set(); should maybe be changed to BOOST_PYTHON_DECL BOOST_ATTRIBUTE_NORETURN void throw_error_already_set(); This will help eliminate warnings on some compilers, and will save people the trouble of writing code like int f() { ... boost::python::throw_error_already_set(); return 0; // unreachable but needed to silence compiler warning } BOOST_ATTRIBUTE_NORETURN is defined in boost/exception/detail/attribute_noreturn.hpp.