Index: uspace/lib/c/generic/io/window.c
===================================================================
--- uspace/lib/c/generic/io/window.c	(revision 62fbb7ef714f1160227d2fa29a651dfab2544a5b)
+++ uspace/lib/c/generic/io/window.c	(revision ee1c2d9cd5399d6bcfa9ffa802a3e8598188074b)
@@ -40,8 +40,9 @@
 #include <stdio.h>
 
-int win_register(async_sess_t *sess, service_id_t *in, service_id_t *out)
+int win_register(async_sess_t *sess, window_flags_t flags, service_id_t *in,
+    service_id_t *out)
 {
 	async_exch_t *exch = async_exchange_begin(sess);
-	int ret = async_req_0_2(exch, WINDOW_REGISTER, in, out);
+	int ret = async_req_1_2(exch, WINDOW_REGISTER, flags, in, out);
 	async_exchange_end(exch);