diff --git a/hardware/arduino/cores/arduino/WString.cpp b/hardware/arduino/cores/arduino/WString.cpp
index b07edc3d5..57e4e8122 100644
--- a/hardware/arduino/cores/arduino/WString.cpp
+++ b/hardware/arduino/cores/arduino/WString.cpp
@@ -1,6 +1,7 @@
 /*
  WString.cpp - String library for Wiring & Arduino
  Copyright (c) 2009-10 Hernando Barragan.  All rights reserved.
+ Changes for version 1.0 by Xiaoyang Feng
  
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
diff --git a/hardware/arduino/cores/arduino/WString.h b/hardware/arduino/cores/arduino/WString.h
index afeb93544..c49e0c56d 100644
--- a/hardware/arduino/cores/arduino/WString.h
+++ b/hardware/arduino/cores/arduino/WString.h
@@ -1,6 +1,8 @@
 /*
  WString.h - String library for Wiring & Arduino
  Copyright (c) 2009-10 Hernando Barragan.  All right reserved.
+ Changes for version 1.0 by Xiaoyang Feng
+
  
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public