diff --git a/lib/groupdate.rb b/lib/groupdate.rb
index eb83b7e..3804556 100644
--- a/lib/groupdate.rb
+++ b/lib/groupdate.rb
@@ -1,5 +1,15 @@
 require "active_support/time"
 require "groupdate/version"
+
+module Groupdate
+  FIELDS = [:second, :minute, :hour, :day, :week, :month, :year, :day_of_week, :hour_of_day]
+  METHODS = FIELDS.map{|v| :"group_by_#{v}" }
+
+  mattr_accessor :week_start, :day_start, :time_zone
+  self.week_start = :sun
+  self.day_start = 0
+end
+
 require "groupdate/magic"
 begin
   require "active_record"
@@ -8,9 +18,3 @@ rescue LoadError
 end
 require "groupdate/active_record" if defined?(ActiveRecord)
 require "groupdate/enumerable"
-
-module Groupdate
-  mattr_accessor :week_start, :day_start, :time_zone
-  self.week_start = :sun
-  self.day_start = 0
-end
diff --git a/lib/groupdate/active_record.rb b/lib/groupdate/active_record.rb
index 0b04f33..a56ceb9 100644
--- a/lib/groupdate/active_record.rb
+++ b/lib/groupdate/active_record.rb
@@ -3,6 +3,25 @@ require "groupdate/scopes"
 
 ActiveRecord::Base.send(:extend, Groupdate::Scopes)
 
+module ActiveRecord
+  class Relation
+
+    if ActiveRecord::VERSION::MAJOR == 3 and ActiveRecord::VERSION::MINOR < 2
+
+      def method_missing_with_hack(method, *args, &block)
+        if Groupdate::METHODS.include?(method)
+          scoping { @klass.send(method, *args, &block) }
+        else
+          method_missing_without_hack(method, *args, &block)
+        end
+      end
+      alias_method_chain :method_missing, :hack
+
+    end
+
+  end
+end
+
 # hack for **unfixed** rails issue
 # https://github.com/rails/rails/issues/7121
 module ActiveRecord
diff --git a/lib/groupdate/enumerable.rb b/lib/groupdate/enumerable.rb
index 93e18b1..250b9e8 100644
--- a/lib/groupdate/enumerable.rb
+++ b/lib/groupdate/enumerable.rb
@@ -1,11 +1,8 @@
 module Enumerable
 
-  # skip due to ActiveRecord bug
-  unless defined?(ActiveRecord) and ActiveRecord::VERSION::MAJOR == 3 and ActiveRecord::VERSION::MINOR < 2
-    [:second, :minute, :hour, :day, :week, :month, :year, :day_of_week, :hour_of_day].each do |field|
-      define_method :"group_by_#{field}" do |options = {}, &block|
-        Groupdate::Magic.new(field, options).group_by(self, &block)
-      end
+  Groupdate::FIELDS.each do |field|
+    define_method :"group_by_#{field}" do |options = {}, &block|
+      Groupdate::Magic.new(field, options).group_by(self, &block)
     end
   end
 
diff --git a/lib/groupdate/scopes.rb b/lib/groupdate/scopes.rb
index 12cb04f..e6e38b4 100644
--- a/lib/groupdate/scopes.rb
+++ b/lib/groupdate/scopes.rb
@@ -5,7 +5,7 @@ require "active_record"
 module Groupdate
   module Scopes
 
-    [:second, :minute, :hour, :day, :week, :month, :year, :day_of_week, :hour_of_day].each do |field|
+    Groupdate::FIELDS.each do |field|
       define_method :"group_by_#{field}" do |*args|
         args = args.dup
         options = args[-1].is_a?(Hash) ? args.pop : {}
diff --git a/test/enumerable_test.rb b/test/enumerable_test.rb
index 722ef8d..4d534e5 100644
--- a/test/enumerable_test.rb
+++ b/test/enumerable_test.rb
@@ -1,23 +1,21 @@
 require_relative "test_helper"
 
-unless ActiveRecord::VERSION::MAJOR == 3 and ActiveRecord::VERSION::MINOR < 2
-  class TestEnumerable < Minitest::Unit::TestCase
-    include TestGroupdate
+class TestEnumerable < Minitest::Unit::TestCase
+  include TestGroupdate
 
-    def test_enumerable
-      user_a = User.new(created_at: utc.parse("2014-01-21"))
-      user_b = User.new(created_at: utc.parse("2014-03-14"))
-      expected = {
-        utc.parse("2014-01-01") => [user_a],
-        utc.parse("2014-02-01") => [],
-        utc.parse("2014-03-01") => [user_b]
-      }
-      assert_equal expected, [user_a, user_b].group_by_month(&:created_at)
-    end
-
-    def call_method(method, field, options)
-      Hash[ User.all.to_a.send(:"group_by_#{method}", options){|u| u.send(field) }.map{|k, v| [k, v.size] } ]
-    end
+  def test_enumerable
+    user_a = User.new(created_at: utc.parse("2014-01-21"))
+    user_b = User.new(created_at: utc.parse("2014-03-14"))
+    expected = {
+      utc.parse("2014-01-01") => [user_a],
+      utc.parse("2014-02-01") => [],
+      utc.parse("2014-03-01") => [user_b]
+    }
+    assert_equal expected, [user_a, user_b].group_by_month(&:created_at)
+  end
 
+  def call_method(method, field, options)
+    Hash[ User.all.to_a.send(:"group_by_#{method}", options){|u| u.send(field) }.map{|k, v| [k, v.size] } ]
   end
+
 end
--
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