diff --git a/drivers/net/ppp_async.c b/drivers/net/ppp_async.c
index 33b9d79..5e48b9a 100644
--- a/drivers/net/ppp_async.c
+++ b/drivers/net/ppp_async.c
@@ -1025,7 +1025,7 @@
 
 static void __exit ppp_async_cleanup(void)
 {
-	if (tty_register_ldisc(N_PPP, NULL) != 0)
+	if (tty_unregister_ldisc(N_PPP) != 0)
 		printk(KERN_ERR "failed to unregister PPP line discipline\n");
 }