diff --git a/ChangeLog b/ChangeLog
index f46b87ea57..51e2a68c79 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Nov  4 04:54:10 2011  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* win32/configure.bat: disable delayed expansion of enironment variable.
+	  [Bug #5517] [ruby-core:40531]
+
 Fri Nov  4 03:45:22 2011  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* io.c (make_writeconv): fixed typo of previous commit.
diff --git a/win32/configure.bat b/win32/configure.bat
index 6eb0320a20..a91de0f33e 100755
--- a/win32/configure.bat
+++ b/win32/configure.bat
@@ -1,4 +1,5 @@
 @echo off
+@setlocal disabledelayedexpansion
 
 echo> ~tmp~.mak ####
 echo>> ~tmp~.mak conf = %0
@@ -206,3 +207,4 @@ echo>>~setup~.mak 	@if exist Makefile ren Makefile Makefile.old
 echo>>~setup~.mak 	@ren Makefile.new Makefile
 nmake -alf ~setup~.mak MAKEFILE=Makefile.new
 :exit
+@endlocal