diff --git a/vendor/golang.org/x/sys/unix/sockcmsg_unix_other.go b/vendor/golang.org/x/sys/unix/sockcmsg_unix_other.go
index 57a0021..0840fe4 100644
--- a/vendor/golang.org/x/sys/unix/sockcmsg_unix_other.go
+++ b/vendor/golang.org/x/sys/unix/sockcmsg_unix_other.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 freebsd linux netbsd openbsd solaris
+//go:build aix || darwin || freebsd || linux || netbsd || openbsd || solaris || zos
+// +build aix darwin freebsd linux netbsd openbsd solaris zos
 
 package unix
 
@@ -36,6 +37,10 @@
 		if runtime.GOOS == "netbsd" && runtime.GOARCH == "arm64" {
 			salign = 16
 		}
+	case "zos":
+		// z/OS socket macros use [32-bit] sizeof(int) alignment,
+		// not pointer width.
+		salign = SizeofInt
 	}
 
 	return (salen + salign - 1) & ^(salign - 1)