diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 8f7f30167d054a4fcc57a75e0ba257ea1d822554..70d7988e94965e3ff343d393c988f5b275bea30e 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,18 @@
+*   Revert `ActiveRecord::Relation#order` change that make new order
+    prepend the old one.
+
+    Before:
+
+        User.order("name asc").order("created_at desc")
+        # SELECT * FROM users ORDER BY created_at desc, name asc
+
+    After:
+
+        User.order("name asc").order("created_at desc")
+        # SELECT * FROM users ORDER BY name asc, created_at desc
+
+    This also affects order defined in `default_scope` or any kind of associations.
+
 *   Add ability to define how a class is converted to Arel predicates.
     For example, adding a very vendor specific regex implementation:
 
diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb
index d0c56ac3d0428b9b008b4e46cab7c36fb64e0626..49b632c4c7c82b20ff6670961832cab91ce14ef0 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -299,7 +299,7 @@ def order!(*args) # :nodoc:
           arg
       }
 
-      self.order_values = args.concat self.order_values
+      self.order_values += args
       self
     end
 
@@ -311,7 +311,7 @@ def order!(*args) # :nodoc:
     #
     #   User.order('email DESC').reorder('id ASC').order('name ASC')
     #
-    # generates a query with 'ORDER BY name ASC, id ASC'.
+    # generates a query with 'ORDER BY id ASC, name ASC'.
     def reorder(*args)
       check_if_method_has_arguments!("reorder", args)
       spawn.reorder!(*args)
diff --git a/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb b/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb
index c63f48e370847a1ed3e6fca00443ce7a26dbafd9..712a77013333e5a81435a4f5a80b00077dde62f8 100644
--- a/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb
@@ -506,9 +506,9 @@ def test_dynamic_find_should_respect_association_order
     assert_equal high_id_jamis, projects(:active_record).developers.find_by_name('Jamis')
   end
 
-  def test_find_should_prepend_to_association_order
+  def test_find_should_append_to_association_order
     ordered_developers = projects(:active_record).developers.order('projects.id')
-    assert_equal ['projects.id', 'developers.name desc, developers.id desc'], ordered_developers.order_values
+    assert_equal ['developers.name desc, developers.id desc', 'projects.id'], ordered_developers.order_values
   end
 
   def test_dynamic_find_all_should_respect_readonly_access
diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index 9c484a8bbedef8e5747066d624ee218e4f935312..ce51853bf31d2e06240cf6d3b70576d70ee37a41 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -253,9 +253,9 @@ def test_find_many_with_merged_options
     assert_equal 2, companies(:first_firm).limited_clients.limit(nil).to_a.size
   end
 
-  def test_find_should_prepend_to_association_order
+  def test_find_should_append_to_association_order
     ordered_clients =  companies(:first_firm).clients_sorted_desc.order('companies.id')
-    assert_equal ['companies.id', 'id DESC'], ordered_clients.order_values
+    assert_equal ['id DESC', 'companies.id'], ordered_clients.order_values
   end
 
   def test_dynamic_find_should_respect_association_order
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index d0f8731b9a9f33032f36822d9dbb19ced04fed69..bf9d395b2dd62f168fd63e3af92d38e8f633fdeb 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -180,7 +180,7 @@ def test_finding_last_with_arel_order
   end
 
   def test_finding_with_order_concatenated
-    topics = Topic.order('title').order('author_name')
+    topics = Topic.order('author_name').order('title')
     assert_equal 4, topics.to_a.size
     assert_equal topics(:fourth).title, topics.first.title
   end
@@ -1183,20 +1183,20 @@ def test_order_by_relation_attribute
   end
 
   def test_default_scope_order_with_scope_order
-    assert_equal 'honda', CoolCar.order_using_new_style.limit(1).first.name
-    assert_equal 'honda', FastCar.order_using_new_style.limit(1).first.name
+    assert_equal 'zyke', CoolCar.order_using_new_style.limit(1).first.name
+    assert_equal 'zyke', FastCar.order_using_new_style.limit(1).first.name
   end
 
   def test_order_using_scoping
     car1 = CoolCar.order('id DESC').scoping do
-      CoolCar.all.merge!(:order => 'id asc').first
+      CoolCar.all.merge!(order: 'id asc').first
     end
-    assert_equal 'honda', car1.name
+    assert_equal 'zyke', car1.name
 
     car2 = FastCar.order('id DESC').scoping do
-      FastCar.all.merge!(:order => 'id asc').first
+      FastCar.all.merge!(order: 'id asc').first
     end
-    assert_equal 'honda', car2.name
+    assert_equal 'zyke', car2.name
   end
 
   def test_unscoped_block_style
diff --git a/activerecord/test/cases/scoping/default_scoping_test.rb b/activerecord/test/cases/scoping/default_scoping_test.rb
index 4bcc97ec44872b6edf3dbd93862662f09234ffd6..2358e2396d2e536df668d0d12614726976b3e828 100644
--- a/activerecord/test/cases/scoping/default_scoping_test.rb
+++ b/activerecord/test/cases/scoping/default_scoping_test.rb
@@ -82,7 +82,7 @@ def test_default_scope_with_multiple_calls
   end
 
   def test_scope_overwrites_default
-    expected = Developer.all.merge!(:order => ' name DESC, salary DESC').to_a.collect { |dev| dev.name }
+    expected = Developer.all.merge!(order: 'salary DESC, name DESC').to_a.collect { |dev| dev.name }
     received = DeveloperOrderedBySalary.by_name.to_a.collect { |dev| dev.name }
     assert_equal expected, received
   end
@@ -94,7 +94,7 @@ def test_reorder_overrides_default_scope_order
   end
 
   def test_order_after_reorder_combines_orders
-    expected = Developer.order('id DESC, name DESC').collect { |dev| [dev.name, dev.id] }
+    expected = Developer.order('name DESC, id DESC').collect { |dev| [dev.name, dev.id] }
     received = Developer.order('name ASC').reorder('name DESC').order('id DESC').collect { |dev| [dev.name, dev.id] }
     assert_equal expected, received
   end
@@ -253,8 +253,8 @@ def test_unscope_errors_with_non_symbol_or_hash_arguments
   end
 
   def test_order_in_default_scope_should_not_prevail
-    expected = Developer.all.merge!(:order => 'salary').to_a.collect { |dev| dev.salary }
-    received = DeveloperOrderedBySalary.all.merge!(:order => 'salary').to_a.collect { |dev| dev.salary }
+    expected = Developer.all.merge!(order: 'salary desc').to_a.collect { |dev| dev.salary }
+    received = DeveloperOrderedBySalary.all.merge!(order: 'salary').to_a.collect { |dev| dev.salary }
     assert_equal expected, received
   end
 
diff --git a/guides/source/active_record_querying.md b/guides/source/active_record_querying.md
index 9252a248b2f9601540278456058d18f5762bcd2d..7fe9b8b4af3a322ae642600cbf08fe84197b822f 100644
--- a/guides/source/active_record_querying.md
+++ b/guides/source/active_record_querying.md
@@ -549,11 +549,11 @@ Client.order("orders_count ASC, created_at DESC")
 Client.order("orders_count ASC", "created_at DESC")
 ```
 
-If you want to call `order` multiple times e.g. in different context, new order will prepend previous one
+If you want to call `order` multiple times e.g. in different context, new order will append previous one
 
 ```ruby
 Client.order("orders_count ASC").order("created_at DESC")
-# SELECT * FROM clients ORDER BY created_at DESC, orders_count ASC
+# SELECT * FROM clients ORDER BY orders_count ASC, created_at DESC
 ```
 
 Selecting Specific Fields
diff --git a/guides/source/upgrading_ruby_on_rails.md b/guides/source/upgrading_ruby_on_rails.md
index 656e6d99563a1545eee2eed682ecbbe2b2fbe13d..73c783085e995ea69023b508ef882b1ed15b4fae 100644
--- a/guides/source/upgrading_ruby_on_rails.md
+++ b/guides/source/upgrading_ruby_on_rails.md
@@ -153,8 +153,6 @@ Rails 4.0 no longer supports loading plugins from `vendor/plugins`. You must rep
 
 * In Rails 4.0 when a column or a table is renamed the related indexes are also renamed. If you have migrations which rename the indexes, they are no longer needed.
 
-* Rails 4.0 has changed how orders get stacked in `ActiveRecord::Relation`. In previous versions of Rails, the new order was applied after the previously defined order. But this is no longer true. Check [Active Record Query guide](active_record_querying.html#ordering) for more information.
-
 * Rails 4.0 has changed `serialized_attributes` and `attr_readonly` to class methods only. You shouldn't use instance methods since it's now deprecated. You should change them to use class methods, e.g. `self.serialized_attributes` to `self.class.serialized_attributes`.
 
 * Rails 4.0 has removed `attr_accessible` and `attr_protected` feature in favor of Strong Parameters. You can use the [Protected Attributes gem](https://github.com/rails/protected_attributes) for a smooth upgrade path.