diff --git a/unix/syscall_bsd.go b/unix/syscall_bsd.go
index 678fb27..95ac394 100644
--- a/unix/syscall_bsd.go
+++ b/unix/syscall_bsd.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build darwin || dragonfly || freebsd || netbsd || openbsd
 // +build darwin dragonfly freebsd netbsd openbsd
 
 // BSD system call wrappers shared by *BSD based systems