diff --git a/common/debug.h b/common/debug.h
index 472dd478..3cbe2092 100644
--- a/common/debug.h
+++ b/common/debug.h
@@ -18,16 +18,17 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #ifndef DEBUG_H
 #define DEBUG_H 1
 
+#include <stdbool.h>
 #include "print.h"
 
 
-/* 
- * Debug output control
- */
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+/*
+ * Debug output control
+ */
 typedef union {
     struct {
         bool enable:1;
@@ -40,19 +41,18 @@ typedef union {
 } debug_config_t;
 
 extern debug_config_t debug_config;
-debug_config_t debug_config  __attribute__ ((weak)) = {};
 
 #ifdef __cplusplus
 }
 #endif
 
+/* for backward compatibility */
 #define debug_enable    (debug_config.enable)
 #define debug_matrix    (debug_config.matrix)
 #define debug_keyboard  (debug_config.keyboard)
 #define debug_mouse     (debug_config.mouse)
 
 
-
 /*
  * Debug print utils
  */
@@ -87,9 +87,8 @@ debug_config_t debug_config  __attribute__ ((weak)) = {};
 #define debug_bin(data)             debug_bin8(data)
 #define debug_bin_reverse(data)     debug_bin8(data)
 
-#else
+#else /* NO_DEBUG */
 
-/* NO_DEBUG */
 #define dprint(s)
 #define dprintln(s)
 #define dprintf(fmt, ...)
@@ -113,6 +112,6 @@ debug_config_t debug_config  __attribute__ ((weak)) = {};
 #define debug_bin(data)
 #define debug_bin_reverse(data)
 
-#endif
+#endif /* NO_DEBUG */
 
 #endif
diff --git a/common/debug_config.h b/common/debug_config.h
deleted file mode 100644
index 28bc34cd..00000000
--- a/common/debug_config.h
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
-Copyright 2013 Jun Wako <wakojun@gmail.com>
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 2 of the License, or
-(at your option) any later version.
-
-This program 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 General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#ifndef DEBUG_CONFIG_H
-#define DEBUG_CONFIG_H 1
-
-#include <stdbool.h>
-
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/* NOTE: Not portable. Bit field order depends on implementation */
-typedef union {
-    struct {
-        bool enable:1;
-        bool matrix:1;
-        bool keyboard:1;
-        bool mouse:1;
-        uint8_t reserved:4;
-    };
-    uint8_t raw;
-} debug_config_t;
-extern debug_config_t debug_config;
-
-/* for backward compatibility */
-#define debug_enable    (debug_config.enable)
-#define debug_matrix    (debug_config.matrix)
-#define debug_keyboard  (debug_config.keyboard)
-#define debug_mouse     (debug_config.mouse)
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif