diff --git a/vendor/golang.org/x/sys/unix/constants.go b/vendor/golang.org/x/sys/unix/constants.go
new file mode 100644
index 0000000..3a6ac64
--- /dev/null
+++ b/vendor/golang.org/x/sys/unix/constants.go
@@ -0,0 +1,13 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// 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
+
+package unix
+
+const (
+	R_OK = 0x4
+	W_OK = 0x2
+	X_OK = 0x1
+)