NIL => NULL
diff --git a/Include/object.h b/Include/object.h
index bf0f625..6ec3cbf 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -643,7 +643,7 @@
objects that don't contain references to other objects or heap memory
this can be the standard function free(). Both macros can be used
wherever a void expression is allowed. The argument must not be a
-NIL pointer. If it may be NIL, use Py_XINCREF/Py_XDECREF instead.
+NULL pointer. If it may be NULL, use Py_XINCREF/Py_XDECREF instead.
The macro _Py_NewReference(op) initialize reference counts to 1, and
in special builds (Py_REF_DEBUG, Py_TRACE_REFS) performs additional
bookkeeping appropriate to the special build.