diff --git a/hw/virtio-9p.h b/hw/virtio-9p.h
index 6a68895..637cea6 100644
--- a/hw/virtio-9p.h
+++ b/hw/virtio-9p.h
@@ -37,6 +37,8 @@
     P9_RXATTRCREATE,
     P9_TREADDIR = 40,
     P9_RREADDIR,
+    P9_TFSYNC = 50,
+    P9_RFSYNC,
     P9_TLOCK = 52,
     P9_RLOCK,
     P9_TGETLOCK = 54,