diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index d974d97..148af34 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -2663,7 +2663,7 @@ static struct hso_device *hso_create_bulk_serial_device(
 	serial->parent = hso_dev;
 	hso_dev->port_data.dev_serial = serial;
 
-	if (port & HSO_PORT_MODEM) {
+	if ((port & HSO_PORT_MASK) == HSO_PORT_MODEM) {
 		num_urbs = 2;
 		serial->tiocmget = kzalloc(sizeof(struct hso_tiocmget),
 					   GFP_KERNEL);