diff --git a/ChangeLog b/ChangeLog
index cf9701c7d4..588cd47da8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue May 14 12:21:28 2013  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* win32/win32.c (NET_LUID): mingw may have NET_LUID and not defined
+	  _IFDEF_.
+
 Tue May 14 03:33:17 2013  Koichi Sasada  <ko1@atdot.net>
 
 	* string.c (rb_str_new_frozen): remove debug print.
diff --git a/win32/win32.c b/win32/win32.c
index 2489942e4d..63453c349e 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -3762,7 +3762,7 @@ str2guid(const char *str, GUID *guid)
 }
 
 /* License: Ruby's */
-#ifndef _IFDEF_
+#if !defined(_IFDEF_) && !defined(__MINGW32__)
     typedef struct {
 	uint64_t Value;
 	struct {