diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c
index 1b1d85306c..49e5aed931 100644
--- a/hw/virtio/vhost-shadow-virtqueue.c
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -111,7 +111,7 @@ static bool vhost_svq_translate_addr(const VhostShadowVirtqueue *svq,
         addrs[i] = map->iova + off;
 
         needle_last = int128_add(int128_make64(needle.translated_addr),
-                                 int128_make64(iovec[i].iov_len));
+                                 int128_makes64(iovec[i].iov_len - 1));
         map_last = int128_make64(map->translated_addr + map->size);
         if (unlikely(int128_gt(needle_last, map_last))) {
             qemu_log_mask(LOG_GUEST_ERROR,