diff --git a/openbsc/src/gsm_04_08.c b/openbsc/src/gsm_04_08.c
index 4d352bc..1f82354 100644
--- a/openbsc/src/gsm_04_08.c
+++ b/openbsc/src/gsm_04_08.c
@@ -3139,7 +3139,7 @@
 {
 	struct gsm_mncc *mode = arg;
 
-	return gsm48_lchan_modify(trans->lchan, mode->lchan_mode, NULL);
+	return gsm48_lchan_modify(trans->lchan, mode->lchan_mode);
 }
 
 static struct downstate {