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/traceback.h b/Include/traceback.h
index 6501600..4c7b8cc 100644
--- a/Include/traceback.h
+++ b/Include/traceback.h
@@ -22,7 +22,7 @@
 
 /* Reveal traceback type so we can typecheck traceback objects */
 PyAPI_DATA(PyTypeObject) PyTraceBack_Type;
-#define PyTraceBack_Check(v) ((v)->ob_type == &PyTraceBack_Type)
+#define PyTraceBack_Check(v) (Py_Type(v) == &PyTraceBack_Type)
 
 #ifdef __cplusplus
 }