diff --git a/ChangeLog b/ChangeLog
index dcf26bb33e..49709f54cc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Aug 31 14:41:30 2005  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* win32/Makefile.sub (OPTFLAGS): default global optimization to
+	  disabled for all VC++ versions.  fixed: [ruby-dev:26897]
+
 Wed Aug 31 10:36:09 2005  Hirokazu Yamamoto  <ocean@m2.ccsnet.ne.jp>
 
 	* process.c (proc_detach, proc_setmaxgroups): missing argument type
diff --git a/win32/Makefile.sub b/win32/Makefile.sub
index 0647b5fc3f..c5c7b49ab5 100644
--- a/win32/Makefile.sub
+++ b/win32/Makefile.sub
@@ -68,10 +68,7 @@ ARCH = $(PROCESSOR_ARCHITECTURE)
 DEBUGFLAGS = -Zi
 !endif
 !if !defined(OPTFLAGS)
-OPTFLAGS = -O2b2x
-!if $(MSC_VER) < 1300
-OPTFLAGS = $(OPTFLAGS)g-
-!endif
+OPTFLAGS = -O2b2xg-
 !endif
 !if !defined(OS)
 OS = mswin32