diff --git a/Include/cellobject.h b/Include/cellobject.h
index fd186e2..1036420 100644
--- a/Include/cellobject.h
+++ b/Include/cellobject.h
@@ -13,7 +13,7 @@
 
 PyAPI_DATA(PyTypeObject) PyCell_Type;
 
-#define PyCell_Check(op) ((op)->ob_type == &PyCell_Type)
+#define PyCell_Check(op) (Py_Type(op) == &PyCell_Type)
 
 PyAPI_FUNC(PyObject *) PyCell_New(PyObject *);
 PyAPI_FUNC(PyObject *) PyCell_Get(PyObject *);