diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG
index 40655c6577..59a4bbea59 100644
--- a/actionpack/CHANGELOG
+++ b/actionpack/CHANGELOG
@@ -1,5 +1,7 @@
 *2.3.0 [Edge]*
 
+* Allow helpers directory to be overridden via ActionController::Base.helpers_dir #1424 [Sam Pohlenz]
+
 * Remove deprecated ActionController::Base#assign_default_content_type_and_charset
 
 * Changed the default of ActionView#render to assume partials instead of files when not given an options hash [DHH]. Examples:
diff --git a/actionpack/lib/action_controller/helpers.rb b/actionpack/lib/action_controller/helpers.rb
index 9cffa07b26..6064931eb8 100644
--- a/actionpack/lib/action_controller/helpers.rb
+++ b/actionpack/lib/action_controller/helpers.rb
@@ -1,13 +1,15 @@
 # FIXME: helper { ... } is broken on Ruby 1.9
 module ActionController #:nodoc:
   module Helpers #:nodoc:
-    HELPERS_DIR = (defined?(RAILS_ROOT) ? "#{RAILS_ROOT}/app/helpers" : "app/helpers")
-
     def self.included(base)
       # Initialize the base module to aggregate its helpers.
       base.class_inheritable_accessor :master_helper_module
       base.master_helper_module = Module.new
 
+      # Set the default directory for helpers
+      base.class_inheritable_accessor :helpers_dir
+      base.helpers_dir = (defined?(RAILS_ROOT) ? "#{RAILS_ROOT}/app/helpers" : "app/helpers")
+
       # Extend base with class methods to declare helpers.
       base.extend(ClassMethods)
 
@@ -88,8 +90,8 @@ module ActionController #:nodoc:
       # When the argument is a module it will be included directly in the template class.
       #   helper FooHelper # => includes FooHelper
       #
-      # When the argument is the symbol <tt>:all</tt>, the controller will include all helpers from 
-      # <tt>app/helpers/**/*.rb</tt> under RAILS_ROOT.
+      # When the argument is the symbol <tt>:all</tt>, the controller will include all helpers beneath
+      # <tt>ActionController::Base.helpers_dir</tt> (defaults to <tt>app/helpers/**/*.rb</tt> under RAILS_ROOT).
       #   helper :all
       #
       # Additionally, the +helper+ class method can receive and evaluate a block, making the methods defined available 
@@ -213,8 +215,8 @@ module ActionController #:nodoc:
 
         # Extract helper names from files in app/helpers/**/*.rb
         def all_application_helpers
-          extract = /^#{Regexp.quote(HELPERS_DIR)}\/?(.*)_helper.rb$/
-          Dir["#{HELPERS_DIR}/**/*_helper.rb"].map { |file| file.sub extract, '\1' }
+          extract = /^#{Regexp.quote(helpers_dir)}\/?(.*)_helper.rb$/
+          Dir["#{helpers_dir}/**/*_helper.rb"].map { |file| file.sub extract, '\1' }
         end
     end
   end
diff --git a/actionpack/test/abstract_unit.rb b/actionpack/test/abstract_unit.rb
index 9623afa89d..76812b94df 100644
--- a/actionpack/test/abstract_unit.rb
+++ b/actionpack/test/abstract_unit.rb
@@ -1,6 +1,7 @@
 $:.unshift(File.dirname(__FILE__) + '/../lib')
 $:.unshift(File.dirname(__FILE__) + '/../../activesupport/lib')
 $:.unshift(File.dirname(__FILE__) + '/fixtures/helpers')
+$:.unshift(File.dirname(__FILE__) + '/fixtures/alternate_helpers')
 
 require 'rubygems'
 require 'yaml'
diff --git a/actionpack/test/controller/helper_test.rb b/actionpack/test/controller/helper_test.rb
index 83e3b085e7..5f36461b89 100644
--- a/actionpack/test/controller/helper_test.rb
+++ b/actionpack/test/controller/helper_test.rb
@@ -1,6 +1,6 @@
 require 'abstract_unit'
 
-ActionController::Helpers::HELPERS_DIR.replace File.dirname(__FILE__) + '/../fixtures/helpers'
+ActionController::Base.helpers_dir = File.dirname(__FILE__) + '/../fixtures/helpers'
 
 class TestController < ActionController::Base
   attr_accessor :delegate_attr
@@ -130,6 +130,20 @@ class HelperTest < Test::Unit::TestCase
     assert methods.include?('foobar')
   end
 
+  def test_all_helpers_with_alternate_helper_dir
+    @controller_class.helpers_dir = File.dirname(__FILE__) + '/../fixtures/alternate_helpers'
+
+    # Reload helpers
+    @controller_class.master_helper_module = Module.new
+    @controller_class.helper :all
+
+    # helpers/abc_helper.rb should not be included
+    assert !master_helper_methods.include?('bare_a')
+
+    # alternate_helpers/foo_helper.rb
+    assert master_helper_methods.include?('baz')
+  end
+
   def test_helper_proxy
     methods = ApplicationController.helpers.methods.map(&:to_s)
 
diff --git a/actionpack/test/fixtures/alternate_helpers/foo_helper.rb b/actionpack/test/fixtures/alternate_helpers/foo_helper.rb
new file mode 100644
index 0000000000..a956fce6fa
--- /dev/null
+++ b/actionpack/test/fixtures/alternate_helpers/foo_helper.rb
@@ -0,0 +1,3 @@
+module FooHelper
+  def baz() end
+end