diff --git a/drivers/usb/serial/cyberjack.c b/drivers/usb/serial/cyberjack.c
index 5f17a3b9916d..80260b08398b 100644
--- a/drivers/usb/serial/cyberjack.c
+++ b/drivers/usb/serial/cyberjack.c
@@ -50,6 +50,7 @@
 #define CYBERJACK_PRODUCT_ID	0x0100
 
 /* Function prototypes */
+static int cyberjack_attach(struct usb_serial *serial);
 static int cyberjack_port_probe(struct usb_serial_port *port);
 static int cyberjack_port_remove(struct usb_serial_port *port);
 static int  cyberjack_open(struct tty_struct *tty,
@@ -77,6 +78,7 @@ static struct usb_serial_driver cyberjack_device = {
 	.description =		"Reiner SCT Cyberjack USB card reader",
 	.id_table =		id_table,
 	.num_ports =		1,
+	.attach =		cyberjack_attach,
 	.port_probe =		cyberjack_port_probe,
 	.port_remove =		cyberjack_port_remove,
 	.open =			cyberjack_open,
@@ -100,6 +102,14 @@ struct cyberjack_private {
 	short		wrsent;		/* Data already sent */
 };
 
+static int cyberjack_attach(struct usb_serial *serial)
+{
+	if (serial->num_bulk_out < serial->num_ports)
+		return -ENODEV;
+
+	return 0;
+}
+
 static int cyberjack_port_probe(struct usb_serial_port *port)
 {
 	struct cyberjack_private *priv;