diff -Naur Python-2.7.9-orig/setup.py Python-2.7.9/setup.py --- Python-2.7.9-orig/setup.py 2014-12-11 13:50:04.196600000 +0300 +++ Python-2.7.9/setup.py 2014-12-11 13:50:04.305800000 +0300 @@ -1574,7 +1574,7 @@ macros = dict() libraries = ['rt'] - if host_platform == 'win32': + if host_platform.startswith(('mingw', 'win')): multiprocessing_srcs = [ '_multiprocessing/multiprocessing.c', '_multiprocessing/semaphore.c', '_multiprocessing/pipe_connection.c', @@ -1591,8 +1591,12 @@ multiprocessing_srcs.append('_multiprocessing/semaphore.c') if sysconfig.get_config_var('WITH_THREAD'): + multiprocessing_libs = [] + if host_platform.startswith(('mingw', 'win')): + multiprocessing_libs += ['ws2_32'] exts.append ( Extension('_multiprocessing', multiprocessing_srcs, define_macros=macros.items(), + libraries=multiprocessing_libs, include_dirs=["Modules/_multiprocessing"])) else: missing.append('_multiprocessing')