diff --git a/ChangeLog b/ChangeLog
index 36ae9165aa..b58fbf1526 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Apr  8 14:23:51 2010  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* include/ruby/win32.h: include errno.h before defining errnos.
+	  see [ruby-core:29314]
+
 Thu Apr  8 11:45:14 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/yaml.rb: use Psych if only it is loaded already.
diff --git a/include/ruby/win32.h b/include/ruby/win32.h
index ebbb32dcc3..cd7353580f 100644
--- a/include/ruby/win32.h
+++ b/include/ruby/win32.h
@@ -401,6 +401,8 @@ extern char *rb_w32_strerror(int);
 /* #undef va_end */
 
 /* winsock error map */
+#include <errno.h>
+
 #ifndef EWOULDBLOCK
 # define EWOULDBLOCK		WSAEWOULDBLOCK
 #endif