diff --git a/ChangeLog b/ChangeLog
index 4ecdef1e31..98eef6d0c8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu May 12 09:07:07 2005  Hirokazu Yamamoto  <ocean@m2.ccsnet.ne.jp>
+
+	* test/ruby/envutil.rb, test/drb/drbtest.rb: can test drb
+	  before install. (backported from HEAD) [ruby-Bugs-1672]
+
 Thu May 12 01:23:55 2005  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* eval.c (rb_eval), parse.y (arg): reduce fixnum range literal at
diff --git a/test/drb/drbtest.rb b/test/drb/drbtest.rb
index 6c4cfe6f77..432c7a78bb 100644
--- a/test/drb/drbtest.rb
+++ b/test/drb/drbtest.rb
@@ -2,21 +2,25 @@ require 'test/unit'
 require 'drb/drb'
 require 'drb/extservm'
 require 'timeout'
-require 'rbconfig'
-
-DRb::DRbServer.new(nil)
+begin
+  loadpath = $:.dup
+  $:.replace($: | [File.expand_path("../ruby", File.dirname(__FILE__))])
+  require 'envutil'
+ensure
+  $:.replace(loadpath)
+end
 
 class DRbService
   @@manager = DRb::ExtServManager.new
-  @@ruby = File.join(
-    Config::CONFIG["bindir"],
-    Config::CONFIG["ruby_install_name"] + Config::CONFIG["EXEEXT"]
-  )
+  @@ruby = EnvUtil.rubybin
   @@ruby += " -d" if $DEBUG
-  @@dir = File.dirname(File.expand_path(__FILE__))
+  def self.add_service_command(nm)
+    dir = File.dirname(File.expand_path(__FILE__))
+    DRb::ExtServManager.command[nm] = "#{@@ruby} #{dir}/#{nm}"
+  end
 
   %w(ut_drb.rb ut_array.rb ut_port.rb ut_large.rb ut_safe1.rb ut_eval.rb).each do |nm|
-    DRb::ExtServManager.command[nm] = "#{@@ruby} #{@@dir}/#{nm}"
+    add_service_command(nm)
   end
   @server = @@server = DRb::DRbServer.new(nil, @@manager, {})
   @@manager.uri = @@server.uri
diff --git a/test/ruby/envutil.rb b/test/ruby/envutil.rb
index 4bae3d9e3b..09c8e3f7f4 100644
--- a/test/ruby/envutil.rb
+++ b/test/ruby/envutil.rb
@@ -1,5 +1,8 @@
 module EnvUtil
   def rubybin
+    if ruby = ENV["RUBY"]
+      return ruby
+    end
     miniruby = "miniruby"
     3.times do
       if File.exist? miniruby or File.exist? miniruby+".exe"