diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 295a603..309038f 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -3321,7 +3321,7 @@
     vq->last_avail_wrap_counter =
         vq->shadow_avail_wrap_counter = !!(idx & 0x8000);
     idx >>= 16;
-    vq->used_idx = idx & 0x7ffff;
+    vq->used_idx = idx & 0x7fff;
     vq->used_wrap_counter = !!(idx & 0x8000);
 }