diff --git a/drivers/isdn/mISDN/l1oip_core.c b/drivers/isdn/mISDN/l1oip_core.c
index 990e6a7e6674..c3b661a666cb 100644
--- a/drivers/isdn/mISDN/l1oip_core.c
+++ b/drivers/isdn/mISDN/l1oip_core.c
@@ -731,10 +731,10 @@ l1oip_socket_thread(void *data)
 	while (!signal_pending(current)) {
 		struct kvec iov = {
 			.iov_base = recvbuf,
-			.iov_len = sizeof(recvbuf),
+			.iov_len = recvbuf_size,
 		};
 		recvlen = kernel_recvmsg(socket, &msg, &iov, 1,
-					 sizeof(recvbuf), 0);
+					 recvbuf_size, 0);
 		if (recvlen > 0) {
 			l1oip_socket_parse(hc, &sin_rx, recvbuf, recvlen);
 		} else {