diff --git a/tun/operateonfd.go b/tun/operateonfd.go
index aab7116..bc80453 100644
--- a/tun/operateonfd.go
+++ b/tun/operateonfd.go
@@ -1,5 +1,5 @@
-//go:build !windows
-// +build !windows
+//go:build darwin || freebsd
+// +build darwin freebsd
 
 /* SPDX-License-Identifier: MIT
  *