diff -rupN Python-2.7.13/Modules/selectmodule.c Python-2.7.13-new/Modules/selectmodule.c --- Python-2.7.13/Modules/selectmodule.c 2016-12-17 21:05:07.000000000 +0100 +++ Python-2.7.13-new/Modules/selectmodule.c 2017-01-21 01:46:07.423597765 +0100 @@ -107,9 +107,9 @@ seq2set(PyObject *seq, fd_set *set, pyli v = PyObject_AsFileDescriptor( o ); if (v == -1) goto finally; -#if defined(_MSC_VER) +#if defined(MS_WIN32) max = 0; /* not used for Win32 */ -#else /* !_MSC_VER */ +#else /* !MS_WIN32 */ if (!_PyIsSelectable_fd(v)) { PyErr_SetString(PyExc_ValueError, "filedescriptor out of range in select()"); @@ -117,7 +117,7 @@ seq2set(PyObject *seq, fd_set *set, pyli } if (v > max) max = v; -#endif /* _MSC_VER */ +#endif /* MS_WIN32 */ FD_SET(v, set); /* add object and its file descriptor to the list */ diff -rupN Python-2.7.13/setup.py Python-2.7.13-new/setup.py --- Python-2.7.13/setup.py 2017-01-21 01:46:07.422597776 +0100 +++ Python-2.7.13-new/setup.py 2017-01-21 01:46:07.424597754 +0100 @@ -680,7 +680,11 @@ class PyBuildExt(build_ext): missing.append('spwd') # select(2); not on ancient System V - exts.append( Extension('select', ['selectmodule.c']) ) + select_libs = [] + if host_platform.startswith(('mingw', 'win')): + select_libs += ['ws2_32'] + exts.append( Extension('select', ['selectmodule.c'], + libraries=select_libs) ) # Fred Drake's interface to the Python parser exts.append( Extension('parser', ['parsermodule.c']) )