diff --git a/vendor/github.com/xdg/stringprep/doc.go b/vendor/github.com/xdg/stringprep/doc.go
new file mode 100644
index 0000000..b319e08
--- /dev/null
+++ b/vendor/github.com/xdg/stringprep/doc.go
@@ -0,0 +1,10 @@
+// Copyright 2018 by David A. Golden. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+// Package stringprep provides data tables and algorithms for RFC-3454,
+// including errata (as of 2018-02).  It also provides a profile for
+// SASLprep as defined in RFC-4013.
+package stringprep