I have found the following in config/suffix.hpp: // // We can't have a working std::wstreambuf if there is no std::locale: // # if defined(BOOST_NO_STD_LOCALE) && !defined(BOOST_NO_STD_WSTREAMBUF) # define BOOST_NO_STD_WSTREAMBUF # endif What is the reasoning behind this? My problem is that I am using Windows CE 6.0 with the supplied standard library, and it has no <locale>, yet still seems to provide a working wstreambuf. The effect is that I can't get boost::wformat, which is annoying, considering that the WinCE API uses only wide characters. I have checked that removing this line works. Is there any way to undefine BOOST_NO_STD_WSTREAMBUF without modifying the source? Yechezkel Mett