PEP 3123: Provide forward compatibility with Python 3.0, while keeping
backwards compatibility. Add Py_Refcnt, Py_Type, Py_Size, and
PyVarObject_HEAD_INIT.
diff --git a/Include/complexobject.h b/Include/complexobject.h
index e59bf2c..3e1cda5 100644
--- a/Include/complexobject.h
+++ b/Include/complexobject.h
@@ -43,7 +43,7 @@
 PyAPI_DATA(PyTypeObject) PyComplex_Type;
 
 #define PyComplex_Check(op) PyObject_TypeCheck(op, &PyComplex_Type)
-#define PyComplex_CheckExact(op) ((op)->ob_type == &PyComplex_Type)
+#define PyComplex_CheckExact(op) (Py_Type(op) == &PyComplex_Type)
 
 PyAPI_FUNC(PyObject *) PyComplex_FromCComplex(Py_complex);
 PyAPI_FUNC(PyObject *) PyComplex_FromDoubles(double real, double imag);