diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index 7b0dec14c8b80..a96677f97d4d9 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -317,7 +317,7 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
 	 */
 	baud = tty_termios_baud_rate(termios);
 
-	serial8250_do_set_termios(port, termios, old);
+	serial8250_do_set_termios(port, termios, NULL);
 
 	tty_termios_encode_baud_rate(termios, baud, baud);