diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 0947f2e20045..fc27f6c72b41 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -712,6 +712,8 @@ static int ubd_add(int n, char **error_out)
 	ubd_dev->queue->queuedata = ubd_dev;
 
 	blk_queue_max_hw_segments(ubd_dev->queue, MAX_SG);
+	if(ubd_dev->cow.file != NULL)
+		blk_queue_max_sectors(ubd_dev->queue, 8 * sizeof(long));
 	err = ubd_disk_register(MAJOR_NR, ubd_dev->size, n, &ubd_gendisk[n]);
 	if(err){
 		*error_out = "Failed to register device";