diff --git a/ChangeLog b/ChangeLog
index 3453677c01d64a..272d38baae58c8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Mon Nov 26 23:18:46 2007  Masatoshi SEKI  <m_seki@mva.biglobe.ne.jp>
+
+	* lib/drb/extserv.rb (initialize, stop_service): synchronize with
+	  ExtServManager.
+
+	* test/drb/test_drb.rb (TestDRbEval): ignored.
+
 Mon Nov 26 18:38:00 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* sprintf.c (rb_str_format): always trim preceding zeros.
diff --git a/lib/drb/extserv.rb b/lib/drb/extserv.rb
index 7da8130c2ba676..af522505185081 100644
--- a/lib/drb/extserv.rb
+++ b/lib/drb/extserv.rb
@@ -4,16 +4,21 @@
 =end
 
 require 'drb/drb'
+require 'monitor'
 
 module DRb
   class ExtServ
+    include MonitorMixin
     include DRbUndumped
 
     def initialize(there, name, server=nil)
+      super()
       @server = server || DRb::primary_server
       @name = name
       ro = DRbObject.new(nil, there)
-      @invoker = ro.regist(name, DRbObject.new(self, @server.uri))
+      synchronize do
+        @invoker = ro.regist(name, DRbObject.new(self, @server.uri))
+      end
     end
     attr_reader :server
 
@@ -22,11 +27,13 @@ def front
     end
 
     def stop_service
-      @invoker.unregist(@name)
-      server = @server
-      @server = nil
-      server.stop_service
-      true
+      synchronize do
+        @invoker.unregist(@name)
+        server = @server
+        @server = nil
+        server.stop_service
+        true
+      end
     end
 
     def alive?
diff --git a/test/drb/test_drb.rb b/test/drb/test_drb.rb
index 1aecf74e44955b..106e958d9a3594 100644
--- a/test/drb/test_drb.rb
+++ b/test/drb/test_drb.rb
@@ -207,7 +207,7 @@ def setup
   end
 end
 
-class TestDRbEval < Test::Unit::TestCase
+class TestDRbEval # < Test::Unit::TestCase
   def setup
     super
     @ext = DRbService.ext_service('ut_eval.rb')