diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index 19970c9..d7a8944 100644
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -800,13 +800,11 @@
 	0,					/*tp_getattro*/
 	0,					/*tp_setattro*/
 	&mmap_as_buffer,			/*tp_as_buffer*/
-	Py_TPFLAGS_HAVE_GETCHARBUFFER,		/*tp_flags*/
+	Py_TPFLAGS_DEFAULT,			/*tp_flags*/
 	0,					/*tp_doc*/
 };
 
 
-#define HASINDEX(o) PyType_HasFeature((o)->ob_type, Py_TPFLAGS_HAVE_INDEX)
-
 /* extract the map size from the given PyObject
 
    Returns -1 on error, with an appropriate Python exception raised. On
@@ -815,7 +813,7 @@
 _GetMapSize(PyObject *o)
 {
 	PyNumberMethods *nb = o->ob_type->tp_as_number;
-	if (nb != NULL && HASINDEX(o) && nb->nb_index != NULL) {
+	if (nb != NULL && nb->nb_index != NULL) {
 		Py_ssize_t i = nb->nb_index(o);
 		if (i==-1 && PyErr_Occurred()) 
 			return -1;