diff --git a/railties/lib/rails.rb b/railties/lib/rails.rb
index aeac85f4b3a988d40fbb9be09502bca33aaf97c2..b7cae9a9accf0ea8f9e4edeec2f97b453f7c91d6 100644
--- a/railties/lib/rails.rb
+++ b/railties/lib/rails.rb
@@ -1,5 +1,9 @@
 require "pathname"
 
+require 'active_support'
+require 'active_support/core_ext/kernel/reporting'
+require 'active_support/core_ext/logger'
+
 require 'rails/initializable'
 require 'rails/application'
 require 'rails/railties_path'
diff --git a/railties/lib/rails/application.rb b/railties/lib/rails/application.rb
index 41ae3f9687b8f4c5da449f05f9b8a292aa720e1d..be71469752a471b30980e7a37e47faf25e4d4ec2 100644
--- a/railties/lib/rails/application.rb
+++ b/railties/lib/rails/application.rb
@@ -93,18 +93,8 @@ def call(env)
     # list. By default, all frameworks (Active Record, Active Support,
     # Action Pack, Action Mailer, and Active Resource) are loaded.
     initializer :require_frameworks do
-      begin
-        require 'active_support'
-        require 'active_support/core_ext/kernel/reporting'
-        require 'active_support/core_ext/logger'
-
-        # TODO: This is here to make Sam Ruby's tests pass. Needs discussion.
-        require 'active_support/core_ext/numeric/bytes'
-        config.frameworks.each { |framework| require(framework.to_s) }
-      rescue LoadError => e
-        # Re-raise as RuntimeError because Mongrel would swallow LoadError.
-        raise e.to_s
-      end
+      require 'active_support/all' unless config.active_support.bare
+      config.frameworks.each { |framework| require(framework.to_s) }
     end
 
     # Set the paths from which Rails will automatically load source files, and
@@ -308,9 +298,6 @@ def call(env)
           base_class.send("#{setting}=", value)
         end
       end
-      config.active_support.each do |setting, value|
-        ActiveSupport.send("#{setting}=", value)
-      end
     end
 
     # Sets +ActionController::Base#view_paths+ and +ActionMailer::Base#template_root+
diff --git a/railties/test/application/configuration_test.rb b/railties/test/application/configuration_test.rb
index a3e191649435b4264388c52180b399921a1689db..fc21d4e5fd319ffab086d97ea3fed07543f20587 100644
--- a/railties/test/application/configuration_test.rb
+++ b/railties/test/application/configuration_test.rb
@@ -44,5 +44,14 @@ def setup
         assert_equal Pathname.new("#{app_path}/app"), Rails.application.root
       end
     end
+
+    test "config.active_support.bare does not require all of ActiveSupport" do
+      add_to_config "config.frameworks = []; config.active_support.bare = true"
+
+      Dir.chdir("#{app_path}/app") do
+        require "#{app_path}/config/environment"
+        assert_raises(NoMethodError, /day/) { 1.day }
+      end
+    end
   end
 end
\ No newline at end of file
diff --git a/railties/test/application/initializer_test.rb b/railties/test/application/initializer_test.rb
index 1b319e8a6dbfef66f70072d6120b856ad143e847..56582c5772c2241ff59083376963a42673c75adf 100644
--- a/railties/test/application/initializer_test.rb
+++ b/railties/test/application/initializer_test.rb
@@ -25,7 +25,9 @@ def setup
         config.frameworks << :action_foo
       end
 
-      assert_raises RuntimeError do
+      require "active_support/core_ext/load_error"
+
+      assert_raises MissingSourceFile do
         Rails.initialize!
       end
     end