This following simple snippet would yield an error with visual studio 2015 for both boost1.60.61: boost/timer/timer.hpp(32): error C2757: 'timer': a symbol with this name already exists and therefore this name cannot be used as a namespace name // compiled with cl.exe /EHsc #define BOOST_TEST_MODULE test #include <boost/test/included/unit_test.hpp> #include <boost/timer/timer.hpp> The following variants are ok // compiled with cl.exe /EHsc #define BOOST_TEST_MODULE test #include <boost/test/unit_test.hpp> #include <boost/timer/timer.hpp> Or // compiled with cl.exe /EHsc #define BOOST_TEST_MODULE test #include <boost/test/included/unit_test.hpp> #include <boost/timer.hpp> It looks like Boost.Test is relying on boost.timer v1, which is deprecated in documentation and conflict with V2.