diff --git a/ChangeLog b/ChangeLog
index cd96cbf69e..d5556b5cbb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Nov 14 17:09:39 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* configure.in (--with-opt-dir): ignore and suppress a warning.
+	  [ruby-dev:39684]
+
 Sat Nov 14 16:43:24 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* hash.c (ruby_setenv): get rid of crash in Solaris 8 and 10.
diff --git a/configure.in b/configure.in
index 9a28d8af99..0552f02dbb 100644
--- a/configure.in
+++ b/configure.in
@@ -2620,6 +2620,9 @@ AC_SUBST(rubyhdrdir)dnl
 AC_SUBST(sitehdrdir)dnl
 AC_SUBST(vendorhdrdir)dnl
 
+AC_ARG_WITH(opt-dir,
+	AS_HELP_STRING([--with-opt-dir=DIR], [add optional headers and libraries DIR]))
+
 AC_ARG_WITH(mantype,
 	AS_HELP_STRING([--with-mantype=TYPE], [specify man page type; TYPE is one of man and doc]),
 		[