diff --git a/cores/esp8266/Arduino.h b/cores/esp8266/Arduino.h
index 9cc4ad08b..6b306eb2f 100644
--- a/cores/esp8266/Arduino.h
+++ b/cores/esp8266/Arduino.h
@@ -212,6 +212,7 @@ void loop(void);
 
 #include "HardwareSerial.h"
 #include "Esp.h"
+#include "debug.h"
 
 uint16_t makeWord(uint16_t w);
 uint16_t makeWord(byte h, byte l);
@@ -229,8 +230,6 @@ long random(long, long);
 void randomSeed(unsigned int);
 long map(long, long, long, long, long);
 
-// Debugging functions
-void hexdump(uint8_t *mem, uint32_t len, uint8_t cols = 16);
 
 #endif
 
diff --git a/cores/esp8266/debug.cpp b/cores/esp8266/debug.cpp
index c42016b04..5e280122e 100644
--- a/cores/esp8266/debug.cpp
+++ b/cores/esp8266/debug.cpp
@@ -1,11 +1,25 @@
-/*
- * debug.c
- *
- *  Created on: 13.05.2015
- *      Author: Markus Sattler
+/* 
+ debug.cpp - debug helper functions
+ Copyright (c) 2015 Markus Sattler. All rights reserved.
+ This file is part of the esp8266 core for Arduino environment.
+ 
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
 #include "Arduino.h"
+#include "debug.h"
 
 void ICACHE_RAM_ATTR hexdump(uint8_t *mem, uint32_t len, uint8_t cols) {
     os_printf("\n[HEXDUMP] Address: 0x%08X len: 0x%X (%d)", mem, len, len);
diff --git a/cores/esp8266/debug.h b/cores/esp8266/debug.h
index a312bfdfd..cf0830d3e 100644
--- a/cores/esp8266/debug.h
+++ b/cores/esp8266/debug.h
@@ -3,6 +3,9 @@
 
 #include <stddef.h>
 // #define DEBUGV(...) ets_printf(__VA_ARGS__)
-#define DEBUGV(...) 
+#define DEBUGV(...)
+
+void hexdump(uint8_t *mem, uint32_t len, uint8_t cols = 16);
+
 
 #endif//ARD_DEBUG_H