diff --git a/drivers/serial/crisv10.c b/drivers/serial/crisv10.c
index c856905bb3bdfc3105ac5eff30de5aad2160c265..20402c604c10fc0a887a1803979f888f1139405c 100644
--- a/drivers/serial/crisv10.c
+++ b/drivers/serial/crisv10.c
@@ -3731,7 +3731,7 @@ rs_ioctl(struct tty_struct *tty, struct file * file,
 		/* This is the ioctl to get RS485 data from user-space */
 		if (copy_to_user((struct serial_rs485 *) arg,
 					rs485data,
-					sizeof(serial_rs485)))
+					sizeof(struct serial_rs485)))
 			return -EFAULT;
 		break;
 	}