The window for having fun with moving files around is closing quickly, so if detail/interlocked.hpp is going to be moved to winapi, now is the time. It makes atomic depend on detail, which doesn't really matter at the moment, but could become relevant at some later date. C:\Projects\boost-git\boost>%boostdep% boost/detail/interlocked.hpp Inclusion report for <boost/detail/interlocked.hpp> (in module detail): from atomic: <boost/atomic/detail/interlocked.hpp> from interprocess: <boost/interprocess/detail/win32_api.hpp> from log: <boost/log/detail/spin_mutex.hpp> from thread: <boost/thread/win32/basic_timed_mutex.hpp> <boost/thread/win32/interlocked_read.hpp> <boost/thread/win32/once.hpp> <boost/thread/win32/shared_mutex.hpp> <boost/thread/win32/thread_primitives.hpp>