Oh, it's not listed by Doc/data/stable_abi.dat and so not checked by Tools/scripts/stable_abi.py. It's implemented explicitly as a function only for the stable ABI: PyObject * PyCFunction_New(PyMethodDef *ml, PyObject *self) { return PyCFunction_NewEx(ml, self, NULL); } So yeah, it should be exported. By the way, I would suggest to move "#define PyCFunction_New(ML, SELF) PyCFunction_NewEx((ML), (SELF), NULL)" to Include/cpython/methodobject.h to clarify that the limited C API should call "PyCFunction_New()" and not call "PyCFunction_NewEx()".