diff --git a/vendor/golang.org/x/sys/unix/env_unix.go b/vendor/golang.org/x/sys/unix/env_unix.go
index 84178b0..29ccc4d 100644
--- a/vendor/golang.org/x/sys/unix/env_unix.go
+++ b/vendor/golang.org/x/sys/unix/env_unix.go
@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
+//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris || zos
+// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris zos
 
 // Unix environment variables.