diff --git a/Include/object.h b/Include/object.h
index afbc68d..05d8d39 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -829,6 +829,9 @@
 PyAPI_FUNC(void) Py_IncRef(PyObject *);
 PyAPI_FUNC(void) Py_DecRef(PyObject *);
 
+PyAPI_DATA(PyTypeObject) PyNone_Type;
+PyAPI_DATA(PyTypeObject) PyNotImplemented_Type;
+
 /*
 _Py_NoneStruct is an object of undefined type which can be used in contexts
 where NULL (nil) is not suitable (since NULL often means 'error').