diff --git a/blk-virtio.c b/blk-virtio.c
index c484ca2..9b7190e 100644
--- a/blk-virtio.c
+++ b/blk-virtio.c
@@ -33,6 +33,7 @@ static struct device device = {
 		.blk_size		= 4096,
 	},
 	.host_features		= (1UL << VIRTIO_BLK_F_GEOMETRY)
+				| (1UL << VIRTIO_BLK_F_RO)
 				| (1UL << VIRTIO_BLK_F_BLK_SIZE),
 };