diff --git a/ChangeLog b/ChangeLog
index 7b08560928..62d112d33a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Aug  1 17:27:32 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* win32/Makefile.sub: needs stddef.h for size_t.  a patch from
+	  Akio Tajima at [ruby-dev:41905].
+
 Sun Aug  1 14:59:04 2010  Tanaka Akira  <akr@fsij.org>
 
 	* ext/pathname/pathname.c (path_sub_ext): Pathname#sub_ext translated
diff --git a/win32/Makefile.sub b/win32/Makefile.sub
index be1ef9eb2c..8562162c6e 100644
--- a/win32/Makefile.sub
+++ b/win32/Makefile.sub
@@ -409,6 +409,7 @@ $(CONFIG_H): $(MKFILES) $(srcdir)/win32/Makefile.sub $(win_srcdir)/Makefile.sub
 #define HAVE_SYS_TYPES_H 1
 #define HAVE_SYS_STAT_H 1
 #define HAVE_STDLIB_H 1
+#define HAVE_STDDEF_H 1
 #define HAVE_STRING_H 1
 #define HAVE_MEMORY_H 1
 !if $(MSC_VER) >= 1400