diff --git a/go/internal/gccgoimporter/backdoor.go b/go/internal/gccgoimporter/backdoor.go
index 4feb0dc6..533fc03d 100644
--- a/go/internal/gccgoimporter/backdoor.go
+++ b/go/internal/gccgoimporter/backdoor.go
@@ -1,3 +1,7 @@
+// Copyright 2018 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.
+
 package gccgoimporter
 
 // This file opens a back door to the parser for golang.org/x/tools/go/gccgoexportdata.