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/py_curses.h b/Include/py_curses.h
index aaff4bd..62d00d8 100644
--- a/Include/py_curses.h
+++ b/Include/py_curses.h
@@ -73,7 +73,7 @@
 	WINDOW *win;
 } PyCursesWindowObject;
 
-#define PyCursesWindow_Check(v)	 ((v)->ob_type == &PyCursesWindow_Type)
+#define PyCursesWindow_Check(v)	 (Py_Type(v) == &PyCursesWindow_Type)
 
 #ifdef CURSES_MODULE
 /* This section is used when compiling _cursesmodule.c */