diff --git a/drivers/tty/isicom.c b/drivers/tty/isicom.c
index c5f06b5..0b2bae1 100644
--- a/drivers/tty/isicom.c
+++ b/drivers/tty/isicom.c
@@ -577,7 +577,7 @@
 		header = inw(base);
 		switch (header & 0xff) {
 		case 0:	/* Change in EIA signals */
-			if (port->port.flags & ASYNC_CHECK_CD) {
+			if (tty_port_check_carrier(&port->port)) {
 				if (port->status & ISI_DCD) {
 					if (!(header & ISI_DCD)) {
 					/* Carrier has been lost  */
@@ -758,10 +758,7 @@
 		outw(channel_setup, base);
 		InterruptTheCard(base);
 	}
-	if (C_CLOCAL(tty))
-		port->port.flags &= ~ASYNC_CHECK_CD;
-	else
-		port->port.flags |= ASYNC_CHECK_CD;
+	tty_port_set_check_carrier(&port->port, !C_CLOCAL(tty));
 
 	/* flow control settings ...*/
 	flow_ctrl = 0;