I don't know C, so don't know if I break something or encountered a typo, but changing: C:\Python26\Lib\site-packages\numpy\f2py\cfuncs.py(259): from: #define size(var, dim...) f2py_size((PyArrayObject *)(capi_ ## var ## _tmp), ##dim, -1) to: #define size(var, dim) f2py_size((PyArrayObject *)(capi_ ## var ## _tmp), ##dim, -1) solved this case