diff --git a/drivers/usb/atm/usbatm.c b/drivers/usb/atm/usbatm.c
index 40380434ba96..9b53e8df4648 100644
--- a/drivers/usb/atm/usbatm.c
+++ b/drivers/usb/atm/usbatm.c
@@ -1349,7 +1349,7 @@ static int __init usbatm_usb_init(void)
 {
 	dbg("%s: driver version %s", __func__, DRIVER_VERSION);
 
-	if (sizeof(struct usbatm_control) > sizeof(((struct sk_buff *) 0)->cb)) {
+	if (sizeof(struct usbatm_control) > FIELD_SIZEOF(struct sk_buff, cb)) {
 		printk(KERN_ERR "%s unusable with this kernel!\n", usbatm_driver_name);
 		return -EIO;
 	}