Hi Edmond and any interested reader, I've successfully patched _socket extension of python 2.5.1 to build on OSF1 V4.0 with gcc 4.1.2. The following construct is put right after #include "Python.h" and #include "structmember.h": #define _POSIX_PII_SOCKET #define _LIBC_POLLUTION_H_ Ivosh Raisr