diff --git a/lib/capybara/poltergeist.rb b/lib/capybara/poltergeist.rb
index 5767e5d..0948050 100644
--- a/lib/capybara/poltergeist.rb
+++ b/lib/capybara/poltergeist.rb
@@ -17,7 +17,6 @@ module Capybara
     require 'capybara/poltergeist/network_traffic'
     require 'capybara/poltergeist/errors'
     require 'capybara/poltergeist/cookie'
-    require 'capybara/poltergeist/util'
   end
 end
 
diff --git a/lib/capybara/poltergeist/client.rb b/lib/capybara/poltergeist/client.rb
index 35fc132..a5e6aae 100644
--- a/lib/capybara/poltergeist/client.rb
+++ b/lib/capybara/poltergeist/client.rb
@@ -14,10 +14,10 @@ module Capybara::Poltergeist
       client
     end
 
-    attr_reader :pid, :port, :path, :window_size, :phantomjs_options
+    attr_reader :pid, :server, :path, :window_size, :phantomjs_options
 
-    def initialize(port, options = {})
-      @port              = port
+    def initialize(server, options = {})
+      @server            = server
       @path              = options[:path]              || PHANTOMJS_NAME
       @window_size       = options[:window_size]       || [1024, 768]
       @phantomjs_options = options[:phantomjs_options] || []
@@ -57,14 +57,12 @@ module Capybara::Poltergeist
     end
 
     def command
-      @command ||= begin
-        parts = [path]
-        parts.concat phantomjs_options
-        parts << PHANTOMJS_SCRIPT
-        parts << port
-        parts.concat window_size
-        parts
-      end
+      parts = [path]
+      parts.concat phantomjs_options
+      parts << PHANTOMJS_SCRIPT
+      parts << server.port
+      parts.concat window_size
+      parts
     end
 
     private
diff --git a/lib/capybara/poltergeist/driver.rb b/lib/capybara/poltergeist/driver.rb
index dc77e3c..6c2a26d 100644
--- a/lib/capybara/poltergeist/driver.rb
+++ b/lib/capybara/poltergeist/driver.rb
@@ -34,14 +34,11 @@ module Capybara::Poltergeist
     end
 
     def server
-      @server ||= Server.new(
-        options.fetch(:port)    { Util.find_available_port },
-        options.fetch(:timeout) { DEFAULT_TIMEOUT          }
-      )
+      @server ||= Server.new(options[:port], options.fetch(:timeout) { DEFAULT_TIMEOUT })
     end
 
     def client
-      @client ||= Client.start(server.port,
+      @client ||= Client.start(server,
         :path              => options[:phantomjs],
         :window_size       => options[:window_size],
         :phantomjs_options => phantomjs_options,
diff --git a/lib/capybara/poltergeist/server.rb b/lib/capybara/poltergeist/server.rb
index e4be0c3..4c47148 100644
--- a/lib/capybara/poltergeist/server.rb
+++ b/lib/capybara/poltergeist/server.rb
@@ -1,19 +1,23 @@
 module Capybara::Poltergeist
   class Server
-    attr_reader :port, :socket, :timeout
+    attr_reader :socket, :fixed_port, :timeout
 
-    def initialize(port, timeout = nil)
-      @port    = port
-      @timeout = timeout
+    def initialize(port = nil, timeout = nil)
+      @fixed_port = fixed_port
+      @timeout    = timeout
       start
     end
 
+    def port
+      @socket.port
+    end
+
     def timeout=(sec)
       @timeout = @socket.timeout = sec
     end
 
     def start
-      @socket = WebSocketServer.new(port, timeout)
+      @socket = WebSocketServer.new(fixed_port, timeout)
     end
 
     def stop
diff --git a/lib/capybara/poltergeist/util.rb b/lib/capybara/poltergeist/util.rb
deleted file mode 100644
index 737a8ed..0000000
--- a/lib/capybara/poltergeist/util.rb
+++ /dev/null
@@ -1,12 +0,0 @@
-require 'socket'
-
-module Capybara::Poltergeist
-  module Util
-    def self.find_available_port
-      server = TCPServer.new('127.0.0.1', 0)
-      server.addr[1]
-    ensure
-      server.close if server
-    end
-  end
-end
diff --git a/lib/capybara/poltergeist/web_socket_server.rb b/lib/capybara/poltergeist/web_socket_server.rb
index c71f68d..2e956bd 100644
--- a/lib/capybara/poltergeist/web_socket_server.rb
+++ b/lib/capybara/poltergeist/web_socket_server.rb
@@ -57,21 +57,26 @@ module Capybara::Poltergeist
     # How many seconds to try to bind to the port for before failing
     BIND_TIMEOUT = 5
 
+    HOST = '127.0.0.1'
+
     attr_reader :port, :parser, :socket, :handler, :server
     attr_accessor :timeout
 
-    def initialize(port, timeout = nil)
-      @port    = port
-      @parser  = Http::Parser.new
-      @server  = start_server
+    def initialize(port = nil, timeout = nil)
       @timeout = timeout
+      @parser  = Http::Parser.new
+      @server  = start_server(port)
     end
 
-    def start_server
+    def port
+      server.addr[1]
+    end
+
+    def start_server(port)
       time = Time.now
 
       begin
-        TCPServer.open(port)
+        TCPServer.open(HOST, port || 0)
       rescue Errno::EADDRINUSE
         if (Time.now - time) < BIND_TIMEOUT
           sleep(0.01)
diff --git a/spec/integration/driver_spec.rb b/spec/integration/driver_spec.rb
index 96af8b9..fe2044b 100644
--- a/spec/integration/driver_spec.rb
+++ b/spec/integration/driver_spec.rb
@@ -54,7 +54,7 @@ module Capybara::Poltergeist
       end
     end
 
-    it 'raises an error and restart the client, if the client dies while executing a command' do
+    it 'raises an error and restarts the client, if the client dies while executing a command' do
       lambda { @driver.browser.command('exit') }.should raise_error(DeadClient)
       @session.visit('/')
       @driver.html.should include('Hello world')
diff --git a/spec/unit/client_spec.rb b/spec/unit/client_spec.rb
index 3979f08..e7901f2 100644
--- a/spec/unit/client_spec.rb
+++ b/spec/unit/client_spec.rb
@@ -2,7 +2,9 @@ require 'spec_helper'
 
 module Capybara::Poltergeist
   describe Client do
-    subject { Client.new(6000) }
+    let(:server) { stub(port: 6000) }
+
+    subject { Client.new(server) }
 
     it 'raises an error if phantomjs is too old' do
       `true` # stubbing $?
@@ -21,7 +23,7 @@ module Capybara::Poltergeist
     end
 
     it 'raises an error if phantomjs returns a non-zero exit code' do
-      subject = Client.new(6000, :path => 'exit 42 && ')
+      subject = Client.new(server, :path => 'exit 42 && ')
       expect { subject.start }.to raise_error(Error)
 
       begin
@@ -32,16 +34,16 @@ module Capybara::Poltergeist
     end
 
     context 'with width and height specified' do
-      subject { Client.new(6000, :window_size => [800, 600]) }
+      subject { Client.new(server, :window_size => [800, 600]) }
 
       it 'starts phantomjs, passing the width and height through' do
         Process.should_receive(:spawn).with("phantomjs", Client::PHANTOMJS_SCRIPT, "6000", "800", "600", out: $stdout)
         subject.start
       end
     end
-    
+
     context 'with a custom phantomjs_logger' do
-      subject { Client.new(6000, :phantomjs_logger => :my_custom_logger, :window_size => [800, 600]) }
+      subject { Client.new(server, :phantomjs_logger => :my_custom_logger, :window_size => [800, 600]) }
 
       it 'starts phantomjs, capturing the STDOUT to custom phantomjs_logger' do
         Process.should_receive(:spawn).with("phantomjs", Client::PHANTOMJS_SCRIPT, "6000", "800", "600", out: :my_custom_logger)
@@ -50,7 +52,7 @@ module Capybara::Poltergeist
     end
 
     context 'with additional command-line options' do
-      subject { Client.new(6000, :phantomjs_options => %w[--ignore-ssl-error=yes --load-images=no]) }
+      subject { Client.new(server, :phantomjs_options => %w[--ignore-ssl-error=yes --load-images=no]) }
 
       it 'passed additional command-line options to phantomjs' do
         Process.should_receive(:spawn).with("phantomjs", '--ignore-ssl-error=yes', '--load-images=no', anything, anything, anything, anything, out: $stdout)
@@ -64,7 +66,7 @@ module Capybara::Poltergeist
           alias old_wait wait
         end
 
-        client = Client.new(1234)
+        client = Client.new(server)
         Process.stub(spawn: 5678)
         client.start