diff --git a/Include/weakrefobject.h b/Include/weakrefobject.h
index 0a659b0..e58c352 100644
--- a/Include/weakrefobject.h
+++ b/Include/weakrefobject.h
@@ -44,10 +44,10 @@
 
 #define PyWeakref_CheckRef(op) PyObject_TypeCheck(op, &_PyWeakref_RefType)
 #define PyWeakref_CheckRefExact(op) \
-        ((op)->ob_type == &_PyWeakref_RefType)
+        (Py_Type(op) == &_PyWeakref_RefType)
 #define PyWeakref_CheckProxy(op) \
-        (((op)->ob_type == &_PyWeakref_ProxyType) || \
-         ((op)->ob_type == &_PyWeakref_CallableProxyType))
+        ((Py_Type(op) == &_PyWeakref_ProxyType) || \
+         (Py_Type(op) == &_PyWeakref_CallableProxyType))
 
 /* This macro calls PyWeakref_CheckRef() last since that can involve a
    function call; this makes it more likely that the function call