diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index f398f162a1fd..a8f4cedde4dc 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1924,6 +1924,13 @@ void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl)
 	struct uart_8250_port *up = up_to_u8250p(port);
 	unsigned char mcr;
 
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		if (serial8250_in_MCR(up) & UART_MCR_RTS)
+			mctrl |= TIOCM_RTS;
+		else
+			mctrl &= ~TIOCM_RTS;
+	}
+
 	mcr = serial8250_TIOCM_to_MCR(mctrl);
 
 	mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;