diff --git a/jws/jws.go b/jws/jws.go
index c6bb7f6..683d2d2 100644
--- a/jws/jws.go
+++ b/jws/jws.go
@@ -2,8 +2,16 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Package jws provides encoding and decoding utilities for
-// signed JWS messages.
+// Package jws provides a partial implementation
+// of JSON Web Signature encoding and decoding.
+// It exists to support the golang.org/x/oauth2 package.
+//
+// See RFC 7515.
+//
+// Deprecated: this package is not intended for public use and might be
+// removed in the future. It exists for internal use only.
+// Please switch to another JWS package or copy this package into your own
+// source tree.
 package jws // import "golang.org/x/oauth2/jws"
 
 import (