diff --git a/app/views/issues/_subtask_list_accordion_partial.html.erb b/app/views/issues/_subtask_list_accordion_partial.html.erb
index d64a112..205cd6f 100644
--- a/app/views/issues/_subtask_list_accordion_partial.html.erb
+++ b/app/views/issues/_subtask_list_accordion_partial.html.erb
@@ -20,7 +20,7 @@
     var _contextMenuShow = contextMenuShow;
     isHideMenuSla = false;
     contextMenuShow = function(event){
-      if ($(event.target).parents("div[id='relations']").size() == 1 || !$("table.list > tbody > tr").is(".idnt-1"))
+      if ($(event.target).parents("div[id='relations']").length == 1 || !$("table.list > tbody > tr").is(".idnt-1"))
       {
         //hide this plugin menu
         isHideMenuSla = true;
diff --git a/assets/javascripts/subtask_list_accordion.js b/assets/javascripts/subtask_list_accordion.js
index 4a9a6d0..1d1d6d2 100644
--- a/assets/javascripts/subtask_list_accordion.js
+++ b/assets/javascripts/subtask_list_accordion.js
@@ -19,7 +19,7 @@ function childIssueShowOrHide(parentTR)
 function seletedTreeOpen()
 {
   var targetParents = slaTRs.filter("tr:has(td.checkbox > input:checked)");
-  for (var i = 0; i < targetParents.size(); i++)
+  for (var i = 0; i < targetParents.length; i++)
   {
     var parentTR = targetParents.eq(i);
     if (!parentTR.hasClass("haschild"))
@@ -39,7 +39,7 @@ function seletedTreeOpen()
 function seletedTreeClose()
 {
   var targetParents = slaTRs.filter("tr:has(td.checkbox > input:checked)");
-  for (var i = 0; i < targetParents.size(); i++)
+  for (var i = 0; i < targetParents.length; i++)
   {
     var parentTR = targetParents.eq(i);
     if (!parentTR.hasClass("haschild"))
@@ -59,7 +59,7 @@ function seletedTreeClose()
 function allExpandNext()
 {
   var parentTR = slaTRs.filter("tr:has(td.checkbox > input:checked)");
-  if (parentTR.size() != 1)
+  if (parentTR.length != 1)
   {
     exit;
   }
@@ -92,7 +92,7 @@ $(document).ready(function()
     slaTRs.show().filter(".haschild").removeClass("collapse").addClass("expand");
     
     //for debug
-    if (slaTRs.filter("tr:visible").size() != slaTRs.size()) alert("NG");
+    if (slaTRs.filter("tr:visible").length != slaTRs.length) alert("NG");
     
     return false;
   });
diff --git a/assets/javascripts/subtask_list_accordion_client.js b/assets/javascripts/subtask_list_accordion_client.js
index 7a46600..a015a72 100644
--- a/assets/javascripts/subtask_list_accordion_client.js
+++ b/assets/javascripts/subtask_list_accordion_client.js
@@ -19,7 +19,7 @@ function getParentIssue(startPos, rank, sameTreeOnly)
   var selectorC = nextAttr + ":first";
   var pp = $(issuesSelector + selectorP + " + " + selectorC);
 
-  if (pp.size() != 1)
+  if (pp.length != 1)
   {
     //no parent
     return $();
@@ -99,7 +99,7 @@ function childIssueShowOrHide(parentTR)
 function setAccordion(parentPos, rank, isHiding, sameTreeOnly)
 {
   var parentTR = getParentIssue(parentPos, rank, sameTreeOnly);
-  if (parentTR.size() != 1)
+  if (parentTR.length != 1)
   {
     return false;
   }
@@ -145,7 +145,7 @@ function setAccordion(parentPos, rank, isHiding, sameTreeOnly)
 function seletedTreeOpen()
 {
   var targetParents = slaTRs.filter("tr:has(td.checkbox > input:checked)");
-  for (var i = 0; i < targetParents.size(); i++)
+  for (var i = 0; i < targetParents.length; i++)
   {
     var parentTR = targetParents.eq(i);
     if (!parentTR.hasClass("haschild"))
@@ -178,7 +178,7 @@ function seletedTreeOpen()
 function seletedTreeClose()
 {
   var targetParents = slaTRs.filter("tr:has(td.checkbox > input:checked)");
-  for (var i = 0; i < targetParents.size(); i++)
+  for (var i = 0; i < targetParents.length; i++)
   {
     var parentTR = targetParents.eq(i);
     if (!parentTR.hasClass("haschild"))
@@ -198,7 +198,7 @@ function seletedTreeClose()
 function allExpandNext()
 {
   var parentTR = slaTRs.filter("tr:has(td.checkbox > input:checked)");
-  if (parentTR.size() != 1)
+  if (parentTR.length != 1)
   {
     exit;
   }
@@ -236,7 +236,7 @@ $(document).ready(function()
   var expandTreeAtFirst = window.subtaskListAccordionExpandTreeAtFirst;
   //make rank first time
   slaTRs = $("table.list > tbody > tr");
-  slaTRsSize = slaTRs.size();
+  slaTRsSize = slaTRs.length;
   var analyzeTo = expandTreeAtFirst ? 10 : 1;
   var isHiding = !expandTreeAtFirst;
   var isSameTreeOnly = isHiding;
@@ -268,7 +268,7 @@ $(document).ready(function()
     slaTRs.show().filter(".haschild").removeClass("collapse").addClass("expand");
     
     //for debug
-    if (slaTRs.filter("tr:visible").size() != slaTRsSize)
+    if (slaTRs.filter("tr:visible").length != slaTRsSize)
     {
       alert("NG");
     }
diff --git a/init.rb b/init.rb
index 1efc84e..a701c2c 100644
--- a/init.rb
+++ b/init.rb
@@ -1,6 +1,6 @@
-require_dependency 'redmine_subtask_list_accordion/hooks/subtask_list_accordion_hook'
-require_dependency 'redmine_subtask_list_accordion/patches/issues_helper_patch'
-require_dependency 'redmine_subtask_list_accordion/patches/user_preference_patch'
+require_dependency File.expand_path('../lib/redmine_subtask_list_accordion/hooks/subtask_list_accordion_hook', __FILE__)
+require_dependency File.expand_path('../lib/redmine_subtask_list_accordion/patches/issues_helper_patch', __FILE__)
+require_dependency File.expand_path('../lib/redmine_subtask_list_accordion/patches/user_preference_patch', __FILE__)
 
 reloader = defined?(ActiveSupport::Reloader) ? ActiveSupport::Reloader : ActionDispatch::Reloader
 reloader.to_prepare do
diff --git a/lib/redmine_subtask_list_accordion/hooks/subtask_list_accordion_hook.rb b/lib/redmine_subtask_list_accordion/hooks/subtask_list_accordion_hook.rb
index 5ba8353..3a31167 100644
--- a/lib/redmine_subtask_list_accordion/hooks/subtask_list_accordion_hook.rb
+++ b/lib/redmine_subtask_list_accordion/hooks/subtask_list_accordion_hook.rb
@@ -1,18 +1,22 @@
-class SubtaskListAccordionHook < Redmine::Hook::ViewListener
-  render_on :view_issues_show_description_bottom, :partial => 'issues/subtask_list_accordion_partial'
-  render_on :view_my_account_preferences, :partial => 'my/subtask_list_accordion_preferences'
-  
-  def view_issues_context_menu_start(context={})
-    if isIssuePage?(context[:back])
-      context[:controller].send(:render_to_string, {
-        :partial => "context_menus/accordion_menu",
-        :locals => context
-      })
+module RedmineSubtaskListAccordion
+  module Hooks
+    class SubtaskListAccordionHook < Redmine::Hook::ViewListener
+      render_on :view_issues_show_description_bottom, :partial => 'issues/subtask_list_accordion_partial'
+      render_on :view_my_account_preferences, :partial => 'my/subtask_list_accordion_preferences'
+      
+      def view_issues_context_menu_start(context={})
+        if isIssuePage?(context[:back])
+          context[:controller].send(:render_to_string, {
+            :partial => "context_menus/accordion_menu",
+            :locals => context
+          })
+        end
+      end
+      
+      private
+      def isIssuePage?(path)
+        path =~ Regexp.new("issues/+[0-9]")
+      end
     end
   end
-  
-  private
-  def isIssuePage?(path)
-    path =~ Regexp.new("issues/+[0-9]")
-  end
 end
diff --git a/lib/redmine_subtask_list_accordion/patches/issues_helper_patch.rb b/lib/redmine_subtask_list_accordion/patches/issues_helper_patch.rb
index 77fd9b8..82a0f06 100644
--- a/lib/redmine_subtask_list_accordion/patches/issues_helper_patch.rb
+++ b/lib/redmine_subtask_list_accordion/patches/issues_helper_patch.rb
@@ -1,4 +1,4 @@
-require_dependency("issues_helper")
+require_dependency 'issues_helper'
 
 module RedmineSubtaskListAccordion
   module Patches
@@ -108,3 +108,5 @@ def sla_use_css
     end
   end
 end
+
+IssuesController.send :helper, RedmineSubtaskListAccordion::Patches::IssuesHelperPatch
diff --git a/lib/redmine_subtask_list_accordion/patches/user_preference_patch.rb b/lib/redmine_subtask_list_accordion/patches/user_preference_patch.rb
index 3df7e0b..249de7c 100644
--- a/lib/redmine_subtask_list_accordion/patches/user_preference_patch.rb
+++ b/lib/redmine_subtask_list_accordion/patches/user_preference_patch.rb
@@ -5,16 +5,22 @@ module Patches
     module UserPreferencePatch
 
       def self.prepended(base)
+        base.send(:include, InstanceMethods)
         base.class_eval do
           if defined? safe_attributes
             safe_attributes :subtasks_default_expand_limit_upper
           end
         end
       end
-
-      def subtasks_default_expand_limit_upper; (self[:subtasks_default_expand_limit_upper] || 0).to_i; end
-      def subtasks_default_expand_limit_upper=(val); self[:subtasks_default_expand_limit_upper] = val; end
-
+      
+      module InstanceMethods
+        def subtasks_default_expand_limit_upper; (self[:subtasks_default_expand_limit_upper] || 0).to_i; end
+        def subtasks_default_expand_limit_upper=(val); self[:subtasks_default_expand_limit_upper] = val; end
+      end
     end
   end
 end
+
+base = UserPreference
+patch = RedmineSubtaskListAccordion::Patches::UserPreferencePatch
+base.send(:prepend, patch) unless base.included_modules.include?(patch)