diff --git a/ChangeLog b/ChangeLog
index e030dfa0f7..d661b1f453 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Thu Sep 23 18:54:39 2010  wanabe  <s.wanabe@gmail.com>
+
+	* tool/config.sub: add mingw64.
+
+	* win32/mkexports.rb (Exports::Mingw64): added.
+
+	* win32/mkexports.rb (Exports::Mingw32): renamed from Exports::Mingw.
+  
 Thu Sep 23 09:01:28 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* vm_insnhelper.c (vm_cref_push): no outer cref is needed for proc
diff --git a/tool/config.sub b/tool/config.sub
index a39437d015..0e1ffea92d 100755
--- a/tool/config.sub
+++ b/tool/config.sub
@@ -723,6 +723,10 @@ case $basic_machine in
 		basic_machine=i386-pc
 		os=-mingw32
 		;;
+	mingw64)
+		basic_machine=i386-pc
+		os=-mingw64
+		;;
 	mingw32ce)
 		basic_machine=arm-unknown
 		os=-mingw32ce
@@ -1276,7 +1280,7 @@ case $os in
 	      | -chorusos* | -chorusrdb* | -cegcc* \
 	      | -cygwin* | -pe* | -psos* | -moss* | -proelf* | -rtems* \
 	      | -mingw32* | -linux-gnu* | -linux-newlib* | -linux-uclibc* \
-	      | -uxpv* | -beos* | -mpeix* | -udk* \
+	      | -uxpv* | -beos* | -mpeix* | -udk* | -mingw64* \
 	      | -interix* | -uwin* | -mks* | -rhapsody* | -darwin* | -opened* \
 	      | -openstep* | -oskit* | -conix* | -pw32* | -nonstopux* \
 	      | -storm-chaos* | -tops10* | -tenex* | -tops20* | -its* \
diff --git a/win32/mkexports.rb b/win32/mkexports.rb
index e96f9339d0..86ba979ddf 100755
--- a/win32/mkexports.rb
+++ b/win32/mkexports.rb
@@ -149,7 +149,7 @@ class Exports::Cygwin < Exports
   end
 end
 
-class Exports::Mingw < Exports::Cygwin
+class Exports::Mingw32 < Exports::Cygwin
   def each_export(objs)
     super
     yield "strcasecmp", "_stricmp"
@@ -157,6 +157,17 @@ class Exports::Mingw < Exports::Cygwin
   end
 end
 
+class Exports::Mingw64 < Exports::Cygwin
+  def each_export(objs)
+    objdump(objs) do |l|
+      next if /@.*@/ =~ l
+      yield $2, !$1 if /\s(?:(T)|[[:upper:]])\s_?((?!Init_|.*_threadptr_|DllMain[@\n]).*)$/ =~ l
+    end
+    yield "strcasecmp", "_stricmp"
+    yield "strncasecmp", "_strnicmp"
+  end
+end
+
 END {
   exports = Exports.extract(ARGV)
   Exports.output {|f| f.puts(*exports)}