diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 2b8d04e67600ad..f19173da64d83c 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -898,6 +898,8 @@ static int ubd_add(int n, char **error_out)
 	if (err)
 		goto out_cleanup_disk;
 
+	ubd_dev->disk = disk;
+
 	return 0;
 
 out_cleanup_disk: