diff --git a/drivers/usb/serial/keyspan.c b/drivers/usb/serial/keyspan.c
index 7c069a02c1d..ea7bba69f4d 100644
--- a/drivers/usb/serial/keyspan.c
+++ b/drivers/usb/serial/keyspan.c
@@ -838,7 +838,7 @@ static void	usa49_indat_callback(struct urb *urb)
 
 	port = (struct usb_serial_port *) urb->context;
 	tty = port->tty;
-	if (urb->actual_length) {
+	if (tty && urb->actual_length) {
 		/* 0x80 bit is error flag */
 		if ((data[0] & 0x80) == 0) {
 			/* no error on any byte */