diff --git a/drivers/tty/amiserial.c b/drivers/tty/amiserial.c
index b88a65c49240..35819e312624 100644
--- a/drivers/tty/amiserial.c
+++ b/drivers/tty/amiserial.c
@@ -1074,7 +1074,7 @@ static int set_serial_info(struct tty_struct *tty, struct serial_state *state,
 		    (new_serial.xmit_fifo_size != state->xmit_fifo_size) ||
 		    ((new_serial.flags & ~ASYNC_USR_MASK) !=
 		     (port->flags & ~ASYNC_USR_MASK))) {
-			tty_unlock();
+			tty_unlock(tty);
 			return -EPERM;
 		}
 		port->flags = ((port->flags & ~ASYNC_USR_MASK) |