diff --git a/lib/sinatra/test.rb b/lib/sinatra/test.rb
index 65c49c51..dcf6e1c5 100644
--- a/lib/sinatra/test.rb
+++ b/lib/sinatra/test.rb
@@ -4,6 +4,10 @@ module Sinatra
   module Test
     include Rack::Utils
 
+    def self.included(base)
+      Sinatra::Default.set(:environment, :test)
+    end
+
     attr_reader :app, :request, :response
 
     def self.deprecate(framework)
diff --git a/test/helper.rb b/test/helper.rb
index 92a1416c..a28fedc8 100644
--- a/test/helper.rb
+++ b/test/helper.rb
@@ -19,10 +19,6 @@ end
 class Test::Unit::TestCase
   include Sinatra::Test
 
-  def setup
-    Sinatra::Default.set :environment, :test
-  end
-
   # Sets up a Sinatra::Base subclass defined with the block
   # given. Used in setup or individual spec methods to establish
   # the application.
diff --git a/test/test_test.rb b/test/test_test.rb
index 8c13303d..0a4dd293 100644
--- a/test/test_test.rb
+++ b/test/test_test.rb
@@ -130,6 +130,12 @@ describe 'Sinatra::Test' do
     assert called
   end
 
+  it 'sets the environment to :test on include' do
+    Sinatra::Default.set(:environment, :production)
+    Class.new { include Sinatra::Test }
+    assert_equal :test, Sinatra::Default.environment
+  end
+
   def test_TestHarness
     session  = Sinatra::TestHarness.new(@app)
     response = session.get('/')