diff --git a/hw/net/rocker/rocker_world.c b/hw/net/rocker/rocker_world.c
index b991e87..a6b18f1 100644
--- a/hw/net/rocker/rocker_world.c
+++ b/hw/net/rocker/rocker_world.c
@@ -32,7 +32,7 @@
         return world->ops->ig(world, pport, iov, iovcnt);
     }
 
-    return iov_size(iov, iovcnt);
+    return -1;
 }
 
 int world_do_cmd(World *world, DescInfo *info,