Compiler warnings in _iomodule.c

./Modules/_io/_iomodule.c:649:15: warning: incompatible function pointer types initializing 'freefunc' (aka 'void (*)(void *)') with an expression of type 'void (PyObject *)' (aka 'void (struct _object *)') [-Wincompatible-function-pointer-types]
    .m_free = iomodule_free,
              ^~~~~~~~~~~~~