diff --git a/init.rb b/init.rb
index c88b3c78..6a523af9 100644
--- a/init.rb
+++ b/init.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 $:.unshift "#{File.dirname(__FILE__)}/lib"
 require "acts_as_list"
diff --git a/lib/acts_as_list.rb b/lib/acts_as_list.rb
index cb56c160..aef6f448 100644
--- a/lib/acts_as_list.rb
+++ b/lib/acts_as_list.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "acts_as_list/active_record/acts/list"
 require "acts_as_list/active_record/acts/position_column_method_definer"
 require "acts_as_list/active_record/acts/scope_method_definer"
diff --git a/lib/acts_as_list/active_record/acts/active_record.rb b/lib/acts_as_list/active_record/acts/active_record.rb
index 46cc1c94..ea33182d 100644
--- a/lib/acts_as_list/active_record/acts/active_record.rb
+++ b/lib/acts_as_list/active_record/acts/active_record.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 ActiveSupport.on_load :active_record do
   extend ActiveRecord::Acts::List::ClassMethods
 end
diff --git a/lib/acts_as_list/active_record/acts/add_new_at_method_definer.rb b/lib/acts_as_list/active_record/acts/add_new_at_method_definer.rb
index 8201bca3..23122084 100644
--- a/lib/acts_as_list/active_record/acts/add_new_at_method_definer.rb
+++ b/lib/acts_as_list/active_record/acts/add_new_at_method_definer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord::Acts::List::AddNewAtMethodDefiner #:nodoc:
   def self.call(caller_class, add_new_at)
     caller_class.class_eval do
diff --git a/lib/acts_as_list/active_record/acts/aux_method_definer.rb b/lib/acts_as_list/active_record/acts/aux_method_definer.rb
index 65f9041a..38517082 100644
--- a/lib/acts_as_list/active_record/acts/aux_method_definer.rb
+++ b/lib/acts_as_list/active_record/acts/aux_method_definer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord::Acts::List::AuxMethodDefiner #:nodoc:
   def self.call(caller_class)
     caller_class.class_eval do
diff --git a/lib/acts_as_list/active_record/acts/callback_definer.rb b/lib/acts_as_list/active_record/acts/callback_definer.rb
index 34be6581..5e7e53ae 100644
--- a/lib/acts_as_list/active_record/acts/callback_definer.rb
+++ b/lib/acts_as_list/active_record/acts/callback_definer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord::Acts::List::CallbackDefiner #:nodoc:
   def self.call(caller_class, add_new_at)
     caller_class.class_eval do
diff --git a/lib/acts_as_list/active_record/acts/list.rb b/lib/acts_as_list/active_record/acts/list.rb
index 9873aae8..6328b521 100644
--- a/lib/acts_as_list/active_record/acts/list.rb
+++ b/lib/acts_as_list/active_record/acts/list.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Acts #:nodoc:
     module List #:nodoc:
diff --git a/lib/acts_as_list/active_record/acts/no_update.rb b/lib/acts_as_list/active_record/acts/no_update.rb
index 5ca7f397..05524c53 100644
--- a/lib/acts_as_list/active_record/acts/no_update.rb
+++ b/lib/acts_as_list/active_record/acts/no_update.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Acts
     module List
diff --git a/lib/acts_as_list/active_record/acts/position_column_method_definer.rb b/lib/acts_as_list/active_record/acts/position_column_method_definer.rb
index 7c9f0ae8..dfb58dd2 100644
--- a/lib/acts_as_list/active_record/acts/position_column_method_definer.rb
+++ b/lib/acts_as_list/active_record/acts/position_column_method_definer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord::Acts::List::PositionColumnMethodDefiner #:nodoc:
   def self.call(caller_class, position_column)
     define_class_methods(caller_class, position_column)
@@ -29,7 +31,7 @@ def self.define_class_methods(caller_class, position_column)
       end
 
       define_singleton_method :update_all_with_touch do |updates|
-        update_all(updates << touch_record_sql)
+        update_all(updates + touch_record_sql)
       end
 
       private
diff --git a/lib/acts_as_list/active_record/acts/scope_method_definer.rb b/lib/acts_as_list/active_record/acts/scope_method_definer.rb
index 1966b25c..fe5af52f 100644
--- a/lib/acts_as_list/active_record/acts/scope_method_definer.rb
+++ b/lib/acts_as_list/active_record/acts/scope_method_definer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord::Acts::List::ScopeMethodDefiner #:nodoc:
   extend ActiveSupport::Inflector
 
diff --git a/lib/acts_as_list/active_record/acts/sequential_updates_method_definer.rb b/lib/acts_as_list/active_record/acts/sequential_updates_method_definer.rb
index 9fb577ba..b744b125 100644
--- a/lib/acts_as_list/active_record/acts/sequential_updates_method_definer.rb
+++ b/lib/acts_as_list/active_record/acts/sequential_updates_method_definer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord::Acts::List::SequentialUpdatesMethodDefiner #:nodoc:
   def self.call(caller_class, column, sequential_updates_option)
     caller_class.class_eval do
diff --git a/lib/acts_as_list/active_record/acts/top_of_list_method_definer.rb b/lib/acts_as_list/active_record/acts/top_of_list_method_definer.rb
index 35a1e230..9d6cb10c 100644
--- a/lib/acts_as_list/active_record/acts/top_of_list_method_definer.rb
+++ b/lib/acts_as_list/active_record/acts/top_of_list_method_definer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord::Acts::List::TopOfListMethodDefiner #:nodoc:
   def self.call(caller_class, top_of_list)
     caller_class.class_eval do
diff --git a/lib/acts_as_list/version.rb b/lib/acts_as_list/version.rb
index 320d3e48..86020931 100644
--- a/lib/acts_as_list/version.rb
+++ b/lib/acts_as_list/version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module Acts
     module List
diff --git a/test/helper.rb b/test/helper.rb
index efa2c78b..cd8374b8 100644
--- a/test/helper.rb
+++ b/test/helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # $DEBUG = true
 
 require "rubygems"
diff --git a/test/shared.rb b/test/shared.rb
index dd23e48a..a477a192 100644
--- a/test/shared.rb
+++ b/test/shared.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Common shared behaviour.
 module Shared
   autoload :List,           'shared_list'
diff --git a/test/shared_array_scope_list.rb b/test/shared_array_scope_list.rb
index 8e24de76..28ae82e1 100644
--- a/test/shared_array_scope_list.rb
+++ b/test/shared_array_scope_list.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Shared
   module ArrayScopeList
     def setup
diff --git a/test/shared_list.rb b/test/shared_list.rb
index 34d2c1e1..369920c4 100644
--- a/test/shared_list.rb
+++ b/test/shared_list.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Shared
   module List
     def setup
diff --git a/test/shared_list_sub.rb b/test/shared_list_sub.rb
index 8861f8c4..42acef09 100644
--- a/test/shared_list_sub.rb
+++ b/test/shared_list_sub.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Shared
   module ListSub
     def setup
diff --git a/test/shared_no_addition.rb b/test/shared_no_addition.rb
index ba904629..4d9b2942 100644
--- a/test/shared_no_addition.rb
+++ b/test/shared_no_addition.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Shared
   module NoAddition
     def setup
diff --git a/test/shared_quoting.rb b/test/shared_quoting.rb
index 6762aca2..9c54df5c 100644
--- a/test/shared_quoting.rb
+++ b/test/shared_quoting.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Shared
   module Quoting
 
diff --git a/test/shared_top_addition.rb b/test/shared_top_addition.rb
index b7f6d32f..28ed434d 100644
--- a/test/shared_top_addition.rb
+++ b/test/shared_top_addition.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Shared
   module TopAddition
     def setup
diff --git a/test/shared_zero_based.rb b/test/shared_zero_based.rb
index 45ebacce..0d53dd90 100644
--- a/test/shared_zero_based.rb
+++ b/test/shared_zero_based.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Shared
   module ZeroBased
     def setup
diff --git a/test/test_joined_list.rb b/test/test_joined_list.rb
index e029230e..a8f2f39b 100644
--- a/test/test_joined_list.rb
+++ b/test/test_joined_list.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'helper'
 
 class Section < ActiveRecord::Base
diff --git a/test/test_list.rb b/test/test_list.rb
index caccf73b..e693340a 100644
--- a/test/test_list.rb
+++ b/test/test_list.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # NOTE: following now done in helper.rb (better Readability)
 require 'helper'
 
diff --git a/test/test_no_update_for_extra_classes.rb b/test/test_no_update_for_extra_classes.rb
index 0525a78c..36ab8276 100644
--- a/test/test_no_update_for_extra_classes.rb
+++ b/test/test_no_update_for_extra_classes.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'helper'
 
 class TodoList < ActiveRecord::Base
diff --git a/test/test_no_update_for_scope_destruction.rb b/test/test_no_update_for_scope_destruction.rb
index f360b996..0073e3d5 100644
--- a/test/test_no_update_for_scope_destruction.rb
+++ b/test/test_no_update_for_scope_destruction.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'helper'
 
 class DestructionTodoList < ActiveRecord::Base
@@ -69,4 +71,4 @@ def test_update_children_when_sibling_destroyed
     end
 
   end
-end
\ No newline at end of file
+end