diff --git a/spec/drb_default_id_conv.rb b/spec/drb_default_id_conv.rb
deleted file mode 100644
index d30f897d..00000000
--- a/spec/drb_default_id_conv.rb
+++ /dev/null
@@ -1,61 +0,0 @@
-require 'drb'
-
-if defined?(JRUBY_VERSION)
-  require 'jruby'
-
-  require 'weakref'
-  class DRb::WeakRefDRbIdConv
-
-    def initialize
-      @id2ref = {}
-    end
-
-    # Convert an object reference id to an object.
-    #
-    # This implementation looks up the reference id in the local object
-    # space and returns the object it refers to.
-    def to_obj(ref)
-      _get(ref) || super
-    end
-
-    # Convert an object into a reference id.
-    #
-    # This implementation returns the object's __id__ in the local
-    # object space.
-    def to_id(obj)
-      (obj.nil? ? nil : _put(obj)) || super
-    end
-
-    def _clean
-      dead = []
-      @id2ref.each {|id,weakref| dead << id unless weakref.weakref_alive?}
-      dead.each {|id| @id2ref.delete(id)}
-    end
-
-    def _put(obj)
-      _clean
-      @id2ref[obj.__id__] = WeakRef.new(obj)
-      obj.__id__
-    end
-
-    def _get(id)
-      weakref = @id2ref[id]
-      if weakref
-        result = weakref.__getobj__ rescue nil
-        if result
-          return result
-        else
-          @id2ref.delete id
-        end
-      end
-      nil
-    end
-    private :_clean, :_put, :_get
-
-  end
-
-  # NOTE: the same default object id converter #DRb::DRbIdConv as in 1.8 mode
-  # (not relying on ObjectSpace which is what #DRb::DRbIdConv does in 1.9) :
-  DRb::DRbServer.default_id_conv(DRb::WeakRefDRbIdConv.new)
-
-end
diff --git a/spec/drb_helper.rb b/spec/drb_helper.rb
index 5a48d930..99ad7491 100644
--- a/spec/drb_helper.rb
+++ b/spec/drb_helper.rb
@@ -5,7 +5,9 @@
 # See the file LICENSE.txt for details.
 #++
 
-require 'rubygems'
+# Prefer gem version we already have on GEM_PATH from parent to ensure using the same version
+# and avoid using outdated stdlib versions < 2.2.3
+gem 'drb'
 require 'drb'
 require 'stringio'
 require 'warbler'
@@ -50,8 +52,6 @@ def stop
   end
 end
 
-require File.expand_path('drb_default_id_conv', File.dirname(__FILE__))
-
 server = WarblerDrbServer.new
 service = DRb.start_service 'druby://127.0.0.1:7890', server
 service.thread.join
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 7f1f6c9c..82e3ad77 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -37,9 +37,6 @@ def capture(&block)
   io.string
 end
 
-require 'drb'
-require File.expand_path('drb_default_id_conv', File.dirname(__FILE__))
-
 module ExampleGroupHelpers
   def run_in_directory(dir)
     before :each do
@@ -106,6 +103,7 @@ def create_git_gem(gem_name)
 
   def run_out_of_process_with_drb
     before :all do
+      require 'drb'
       DRb.start_service
       @orig_dir = Dir.pwd
     end
@@ -114,11 +112,11 @@ def run_out_of_process_with_drb
       drb
       DRbObject.new(nil, 'druby://127.0.0.1:7890').tap do |drbclient|
         ready, error = nil, nil
-        300.times do # timeout 30 secs (300 * 0.1)
+        600.times do # timeout 30 secs (600 * 0.05)
           begin
             break if ready = drbclient.ready?
           rescue DRb::DRbConnError => e
-            error = e; sleep 0.1
+            error = e; sleep 0.05
           end
         end
         raise error unless ready
@@ -129,7 +127,7 @@ def run_out_of_process_with_drb
       require 'jruby'
       let(:drb) do
         drb_thread = Thread.new do
-          ruby "-I#{Warbler::WARBLER_HOME}/lib", File.join(@orig_dir, 'spec/drb_helper.rb')
+          ruby '--dev', "-I#{Warbler::WARBLER_HOME}/lib", File.join(@orig_dir, 'spec/drb_helper.rb')
         end
         drb_thread.run
         drb_thread
@@ -147,6 +145,10 @@ def run_out_of_process_with_drb
         drb.stop
       end
     end
+
+    after :all do
+      DRb.stop_service
+    end
   end
 
   def use_test_webserver