diff --git a/debug.go b/debug.go
index 9781e48..df1f81b 100644
--- a/debug.go
+++ b/debug.go
@@ -1,3 +1,7 @@
+// Copyright 2015 The Chihaya Authors. All rights reserved.
+// Use of this source code is governed by the BSD 2-Clause license,
+// which can be found in the LICENSE file.
+
 package chihaya
 
 import (