diff --git a/flowerbox.gemspec b/flowerbox.gemspec
index 2423b1b..dcceada 100644
--- a/flowerbox.gemspec
+++ b/flowerbox.gemspec
@@ -28,7 +28,6 @@ Gem::Specification.new do |gem|
   gem.add_dependency 'jasmine-core'
   gem.add_dependency 'thor'
   gem.add_dependency 'selenium-webdriver'
-  gem.add_dependency 'sinatra'
   gem.add_dependency 'rainbow'
   gem.add_dependency 'sprockets'
   gem.add_dependency 'sprockets-vendor_gems'
diff --git a/lib/flowerbox/rack.rb b/lib/flowerbox/rack.rb
index 1b33fb4..37bc492 100644
--- a/lib/flowerbox/rack.rb
+++ b/lib/flowerbox/rack.rb
@@ -1,34 +1,20 @@
-require 'sinatra'
-require 'cgi'
-
 module Flowerbox
-  class Rack < Sinatra::Base
-    class << self
-      attr_accessor :runner, :sprockets
+  class Rack
+    attr_accessor :runner, :sprockets
+
+    def initialize(runner, sprockets)
+      @runner, @sprockets = runner, sprockets
     end
 
-    def sprockets
-      self.class.sprockets
+    def call(env)
+      dup._call(env)
     end
 
-    def runner
-      self.class.runner
-    end
-
-    get %r{^/__F__/(.*)$} do |file|
-      asset = sprockets.asset_for(file, :bundle => false)
-
-      halt(404) if !asset
-
-      content_type asset.content_type
-      asset.body
-    end
-
-    get '/' do
-      begin
-        runner.template
-      rescue Flowerbox::Runner::Base::RunnerDiedError => e
-        e.message
+    def _call(env)
+      if sprockets_file = env['PATH_INFO'][%r{/__F__(.*)$}, 1]
+        sprockets.call(env.merge('PATH_INFO' => sprockets_file))
+      else
+        [ 200, { 'Content-type' => 'text/html' }, [ runner.template ] ]
       end
     end
   end
diff --git a/lib/flowerbox/runner/base.rb b/lib/flowerbox/runner/base.rb
index e39d763..61d0275 100644
--- a/lib/flowerbox/runner/base.rb
+++ b/lib/flowerbox/runner/base.rb
@@ -131,14 +131,15 @@ module Flowerbox
       def server
         require 'flowerbox/rack'
 
-        Flowerbox::Rack.runner = self
-        Flowerbox::Rack.sprockets = @sprockets
-
-        return Flowerbox.server if Flowerbox.server
+        if Flowerbox.server
+          Flowerbox.server.app.runner = self
+          Flowerbox.server.app.sprockets = sprockets
+          return Flowerbox.server
+        end
 
         require 'flowerbox/server'
 
-        server_options = { :app => Flowerbox::Rack }
+        server_options = { :app => Flowerbox::Rack.new(self, sprockets) }
         server_options[:logging] = true if options[:verbose_server]
         server_options[:port] = Flowerbox.port
 
diff --git a/lib/flowerbox/sprockets_handler.rb b/lib/flowerbox/sprockets_handler.rb
index 82b5108..7f7f613 100644
--- a/lib/flowerbox/sprockets_handler.rb
+++ b/lib/flowerbox/sprockets_handler.rb
@@ -10,7 +10,7 @@ module Flowerbox
 
     attr_reader :files, :options
 
-    def_delegators :environment, :append_path, :register_engine, :[]
+    def_delegators :environment, :append_path, :register_engine, :[], :call
 
     def self.gem_asset_paths
       @gem_asset_paths ||= Sprockets.find_gem_vendor_paths
@@ -29,7 +29,7 @@ module Flowerbox
     end
 
     def assets_for(asset)
-      environment.find_asset(asset, :bundle => false).to_a
+      environment.find_asset(asset, :bundle => true).to_a
     end
 
     def expire_index!