diff --git a/ChangeLog b/ChangeLog
index f5c8ca8712..13059b0d95 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Fri Jul 16 12:06:08 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* tool/rbinstall.rb (ext-arch): prune directories start with '-'.
+
 Wed Jul 14 18:18:05 2010  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* regexec.c (match_at): add end point to enclen's argument.
diff --git a/tool/rbinstall.rb b/tool/rbinstall.rb
index adbe691cf9..f5586fe1f0 100755
--- a/tool/rbinstall.rb
+++ b/tool/rbinstall.rb
@@ -338,7 +338,7 @@ end
 
 install?(:ext, :arch, :'ext-arch') do
   prepare "extension objects", archlibdir
-  noinst = %w[-*] | (CONFIG["no_install_files"] || "").split
+  noinst = %w[-* -*/] | (CONFIG["no_install_files"] || "").split
   install_recursive("#{$extout}/#{CONFIG['arch']}", archlibdir, :no_install => noinst, :mode => $prog_mode, :strip => $strip)
   prepare "extension objects", sitearchlibdir
   prepare "extension objects", vendorarchlibdir