diff --git a/ChangeLog b/ChangeLog
index febeeafac6..ceb9e9f953 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Mar  7 10:39:04 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* tool/rbinstall.rb (gem): Gem.ensure_gem_subdirectories now has mode
+	  option since r39607.  refix of r38870.
+
 Wed Mar  6 13:14:28 2013  Eric Hodel  <drbrain@segment7.net>
 
 	* test/rubygems/test_gem_spec_fetcher.rb:  Removed unused variable.
diff --git a/tool/rbinstall.rb b/tool/rbinstall.rb
index 0febf203dc..4e24645ea2 100755
--- a/tool/rbinstall.rb
+++ b/tool/rbinstall.rb
@@ -688,8 +688,7 @@ install?(:ext, :comm, :gem) do
   $:.unshift(File.join(srcdir, "lib"))
   require("rubygems.rb")
   gem_dir = Gem.default_dir
-  # Gem.ensure_gem_subdirectories makes subdirectories group-writable.
-  directories = Gem::REPOSITORY_SUBDIRECTORIES
+  directories = Gem.ensure_gem_subdirectories(gem_dir, :mode => $dir_mode)
   prepare "default gems", gem_dir, directories
 
   spec_dir = File.join(gem_dir, directories.grep(/^spec/)[0])