diff --git a/Gemfile b/Gemfile
index ea74dde..c63fead 100644
--- a/Gemfile
+++ b/Gemfile
@@ -21,7 +21,10 @@
 
 source 'https://rubygems.org'
 
-# In order to the plugin in Redmine < 4 (Rails < 5), comment out the following lines
-# I don't know how to check Redmine or better Rails version here :-(
 gem 'acts_as_list'
 gem 'activemodel-serializers-xml'
+
+# Redmine extensions
+unless %w(easyproject easy_gantt).any? { |plugin| Dir.exist?(File.expand_path("../../#{plugin}", __FILE__)) }
+  gem 'redmine_extensions', '~> 0.2.5'
+end
diff --git a/after_init.rb b/after_init.rb
new file mode 100644
index 0000000..3d9c552
--- /dev/null
+++ b/after_init.rb
@@ -0,0 +1,40 @@
+# encoding: utf-8
+#
+# Redmine plugin for Custom Workflows
+#
+# Copyright Anton Argirov
+# Copyright Karel Pičman <karel.picman@kontron.com>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+require_dependency File.dirname(__FILE__) + '/lib/redmine_custom_workflows.rb'
+
+ActiveSupport::Dependencies.autoload_paths << File.join(File.dirname(__FILE__), 'app')
+
+def custom_workflows_init
+  # Administration menu extension
+  Redmine::MenuManager.map :admin_menu do |menu|
+    menu.push :custom_workflows, { controller: 'custom_workflows', action: 'index'},
+         caption: :label_custom_workflow_plural, html: { class: 'icon icon-custom-workflows'}
+  end
+end
+
+if Redmine::Plugin.installed?(:easy_extensions)
+  ActiveSupport.on_load(:easyproject, yield: true) do
+    custom_workflows_init
+  end
+else
+  custom_workflows_init
+end
diff --git a/assets/stylesheets/custom_workflows.css b/assets/stylesheets/custom_workflows.css
new file mode 100644
index 0000000..2b41b2f
--- /dev/null
+++ b/assets/stylesheets/custom_workflows.css
@@ -0,0 +1,64 @@
+/*
+* Redmine plugin for Document Management System "Features"
+*
+* Copyright Anton Argirov
+* Copyright Karel Pičman <karel.picman@kontron.com>
+*
+* This program is free software; you can redistribute it and/or
+* modify it under the terms of the GNU General Public License
+* as published by the Free Software Foundation; either version 2
+* of the License, or (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program; if not, write to the Free Software
+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+
+#tab-content-custom_workflows .disabled {
+    color: silver;
+}
+
+table.list.custom-workflows td {
+    vertical-align: middle;
+}
+
+table.list.custom-workflows td.description {
+    text-align: left;
+    width: 40%;
+}
+
+table.list.custom-workflows td.buttons {
+    white-space: normal;
+    width: 10%;
+    text-align: left;
+}
+
+table.list.custom-workflows tr.disabled {
+    color: silver;
+}
+
+#custom_workflow_description, #custom_workflow_name {
+    width: 98%;
+}
+
+.custom_workflow_script {
+    width: 98%;
+    font-size: 11px;
+}
+
+#custom_workflow_enabled_projects ul {
+    max-height: 200px;
+    overflow-y: auto;
+}
+
+/* Icons */
+.icon-export { background-image: url(../images/export.png); }
+.icon-import { background-image: url(../images/import.png); }
+.icon-active { background-image: url(../images/active.png); }
+.icon-inactive { background-image: url(../images/inactive.png); }
+.icon-custom-workflows { background-image: url(../../../images/ticket_go.png); }
\ No newline at end of file
diff --git a/db/migrate/20150526132244_create_example_workflow.rb b/db/migrate/20150526132244_create_example_workflow.rb
index d892653..0d7051b 100644
--- a/db/migrate/20150526132244_create_example_workflow.rb
+++ b/db/migrate/20150526132244_create_example_workflow.rb
@@ -23,38 +23,43 @@ class CreateExampleWorkflow < ActiveRecord::Migration[4.2]
 
   def up
     CustomWorkflow.reset_column_information
-    old = CustomWorkflow.where(:name => 'Duration/Done Ratio/Status correlation').first
+    name = 'Duration/Done Ratio/Status correlation'
+    old = CustomWorkflow.where(name: name).first
     old.destroy if old
+    cw = CustomWorkflow.new
+    cw.name = name
+    cw.author = 'anton.argirov@gmail.com'
+    cw.description = %{
+      Set up a correlation between the start date, due date, done ratio and status of issues.
 
-    CustomWorkflow.create!(:name => 'Duration/Done Ratio/Status correlation', :author => 'anton.argirov@gmail.com', :description => <<EOD, :before_save => <<EOS)
-Set up a correlation between the start date, due date, done ratio and status of issues.
+      * If done ratio is changed to 100% and status is "In Process", status changes to "Resolved"
+      * If status is "New", "Resolved" or "Feedback" and done ratio is changed to value less than 100%, status changes to "In process"
+      * If status is changed to "In process" and start date is not set, then it sets to current date
+      * If status is changed to "Resolved" and end date is not set, then it set to due date
 
-* If done ratio is changed to 100% and status is "In Process", status changes to "Resolved"
-* If status is "New", "Resolved" or "Feedback" and done ratio is changed to value less than 100%, status changes to "In process"
-* If status is changed to "In process" and start date is not set, then it sets to current date
-* If status is changed to "Resolved" and end date is not set, then it set to due date
+      To use this script properly, turn off "Use current date as start date for new issues" option in the settings as this script already do it own way.
+    }
+    cw.before_save = %{
+      if @issue.done_ratio_changed?
+        if (@issue.done_ratio == 100) && (@issue.status_id == 2)
+          @issue.status_id = 3
+        elsif [1,3,4].include?(@issue.status_id) && (@issue.done_ratio < 100)
+          @issue.status_id = 2
+        end
+      end
 
-To use this script properly, turn off "Use current date as start date for new issues" option in the settings as this script already do it own way.
-EOD
-if @issue.done_ratio_changed?
-  if @issue.done_ratio==100 && @issue.status_id==2
-    @issue.status_id=3
-  elsif [1,3,4].include?(@issue.status_id) && @issue.done_ratio<100
-    @issue.status_id=2
-  end
-end
-
-if @issue.status_id_changed?
-  if @issue.status_id==2
-    @issue.start_date ||= Time.now
-  end
-  if @issue.status_id==3
-    @issue.done_ratio = 100
-    @issue.start_date ||= @issue.created_on
-    @issue.due_date ||= Time.now
-  end
-end
-EOS
+      if @issue.status_id_changed?
+        if @issue.status_id == 2
+          @issue.start_date ||= Time.now
+        end
+        if @issue.status_id == 3
+          @issue.done_ratio = 100
+          @issue.start_date ||= @issue.created_on
+          @issue.due_date ||= Time.now
+        end
+      end
+    }
+    cw.save!
   end
 
 end
diff --git a/init.rb b/init.rb
index 7f35058..54c2126 100644
--- a/init.rb
+++ b/init.rb
@@ -19,24 +19,25 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
-require 'redmine'
-
 Redmine::Plugin.register :redmine_custom_workflows do
-  name 'Redmine Custom Workflow plugin'
+  if Redmine::Plugin.installed?(:easy_extensions)
+    name 'Easy Custom Workflow plugin'
+    url 'https://www.easyredmine.com'
+    author_url 'https://www.easyredmine.com'
+  else
+    name 'Redmine Custom Workflow plugin'
+    url 'https://www.redmine.org/plugins/custom-workflows'
+    author_url 'https://github.com/danmunn/redmine_custom_workflows/graphs/contributors'
+  end
   author 'Anton Argirov/Karel Pičman'
-  description 'Allows to create custom workflows for issues, defined in the plain Ruby language'
+  description 'Allows to create custom workflows for objects, defined in the plain Ruby language'
   version '1.0.1'
-  url 'http://www.redmine.org/plugins/custom-workflows'
 
   requires_redmine version_or_higher: '4.0.0'
 
   permission :manage_project_workflow, {}, :require => :member
 end
 
-require_dependency File.dirname(__FILE__) + '/lib/redmine_custom_workflows.rb'
-
-# Administration menu extension
-Redmine::MenuManager.map :admin_menu do |menu|
-  menu.push :custom_workflows, { controller: 'custom_workflows', action: 'index'},
-       caption: :label_custom_workflow_plural, html: { class: 'icon icon-workflows'}
+unless Redmine::Plugin.installed?(:easy_extensions)
+  require_relative 'after_init'
 end
diff --git a/lib/redmine_custom_workflows/hooks/hooks.rb b/lib/redmine_custom_workflows/hooks/hooks.rb
index 454b59f..d3f7cba 100644
--- a/lib/redmine_custom_workflows/hooks/hooks.rb
+++ b/lib/redmine_custom_workflows/hooks/hooks.rb
@@ -22,9 +22,20 @@
 module RedmineCustomWorkflows
 
   class Hooks < Redmine::Hook::ViewListener
+
     def view_layouts_base_html_head(context)
-      stylesheet_link_tag :style, :plugin => 'redmine_custom_workflows'
+      return if defined?(EasyExtensions)
+      "\n".html_safe + stylesheet_link_tag('custom_workflows.css', plugin: :redmine_custom_workflows)
     end
+
+    def easy_extensions_javascripts_hook(context={})
+      context[:template].require_asset('tab_override.js')
+    end
+
+    def easy_extensions_stylesheets_hook(context={})
+      context[:template].require_asset('custom_workflows.css')
+    end
+
   end
 
 end
\ No newline at end of file
diff --git a/lib/redmine_custom_workflows/patches/attachment_patch.rb b/lib/redmine_custom_workflows/patches/attachment_patch.rb
index 85f4fa2..e73fbd1 100644
--- a/lib/redmine_custom_workflows/patches/attachment_patch.rb
+++ b/lib/redmine_custom_workflows/patches/attachment_patch.rb
@@ -24,7 +24,6 @@ module RedmineCustomWorkflows
     module AttachmentPatch
 
       def self.included(base)
-        base.send(:include, InstanceMethods)
         base.class_eval do
           before_save :before_save_custom_workflows
           after_save :after_save_custom_workflows
@@ -33,37 +32,33 @@ module RedmineCustomWorkflows
         end
       end
 
-      module InstanceMethods
+      def before_save_custom_workflows
+        @attachment = self
+        @saved_attributes = attributes.dup
+        CustomWorkflow.run_shared_code(self)
+        CustomWorkflow.run_custom_workflows(:attachment, self, :before_save)
+        throw :abort if errors.any?
+        errors.empty? && (@saved_attributes == attributes || valid?)
+      ensure
+        @saved_attributes = nil
+      end
 
-        def before_save_custom_workflows
-          @attachment = self
-          @saved_attributes = attributes.dup
-          CustomWorkflow.run_shared_code(self)
-          CustomWorkflow.run_custom_workflows(:attachment, self, :before_save)
-          throw :abort if errors.any?
-          errors.empty? && (@saved_attributes == attributes || valid?)
-        ensure
-          @saved_attributes = nil
-        end
+      def after_save_custom_workflows
+        CustomWorkflow.run_custom_workflows(:attachment, self, :after_save)
+      end
 
-        def after_save_custom_workflows
-          CustomWorkflow.run_custom_workflows(:attachment, self, :after_save)
-        end
-
-        def before_destroy_custom_workflows
-          CustomWorkflow.run_custom_workflows(:attachment, self, :before_destroy)
-        end
-
-        def after_destroy_custom_workflows
-          CustomWorkflow.run_custom_workflows(:attachment, self, :after_destroy)
-        end
+      def before_destroy_custom_workflows
+        CustomWorkflow.run_custom_workflows(:attachment, self, :before_destroy)
+      end
 
+      def after_destroy_custom_workflows
+        CustomWorkflow.run_custom_workflows(:attachment, self, :after_destroy)
       end
 
     end
   end
 end
 
-unless Attachment.include?(RedmineCustomWorkflows::Patches::AttachmentPatch)
-  Attachment.send(:include, RedmineCustomWorkflows::Patches::AttachmentPatch)
-end
\ No newline at end of file
+# Apply patch
+RedmineExtensions::PatchManager.register_model_patch 'Attachment',
+  'RedmineCustomWorkflows::Patches::AttachmentPatch'
\ No newline at end of file
diff --git a/lib/redmine_custom_workflows/patches/group_patch.rb b/lib/redmine_custom_workflows/patches/group_patch.rb
index 464e6df..de7d18c 100644
--- a/lib/redmine_custom_workflows/patches/group_patch.rb
+++ b/lib/redmine_custom_workflows/patches/group_patch.rb
@@ -24,7 +24,6 @@ module RedmineCustomWorkflows
     module GroupPatch
 
       def self.included(base)
-        base.send(:include, InstanceMethods)
         base.class_eval do
           before_save :before_save_custom_workflows
           after_save :after_save_custom_workflows
@@ -47,37 +46,33 @@ module RedmineCustomWorkflows
         end
       end
 
-      module InstanceMethods
+      def before_save_custom_workflows
+        @group = self
+        @saved_attributes = attributes.dup
+        CustomWorkflow.run_shared_code(self)
+        CustomWorkflow.run_custom_workflows(:group, self, :before_save)
+        throw :abort if errors.any?
+        errors.empty? && (@saved_attributes == attributes || valid?)
+      ensure
+        @saved_attributes = nil
+      end
 
-        def before_save_custom_workflows
-          @group = self
-          @saved_attributes = attributes.dup
-          CustomWorkflow.run_shared_code(self)
-          CustomWorkflow.run_custom_workflows(:group, self, :before_save)
-          throw :abort if errors.any?
-          errors.empty? && (@saved_attributes == attributes || valid?)
-        ensure
-          @saved_attributes = nil
-        end
+      def after_save_custom_workflows
+        CustomWorkflow.run_custom_workflows(:group, self, :after_save)
+      end
 
-        def after_save_custom_workflows
-          CustomWorkflow.run_custom_workflows(:group, self, :after_save)
-        end
-
-        def before_destroy_custom_workflows
-          CustomWorkflow.run_custom_workflows(:group, self, :before_destroy)
-        end
-
-        def after_destroy_custom_workflows
-          CustomWorkflow.run_custom_workflows(:group, self, :after_destroy)
-        end
+      def before_destroy_custom_workflows
+        CustomWorkflow.run_custom_workflows(:group, self, :before_destroy)
+      end
 
+      def after_destroy_custom_workflows
+        CustomWorkflow.run_custom_workflows(:group, self, :after_destroy)
       end
 
     end
   end
 end
 
-unless Group.include?(RedmineCustomWorkflows::Patches::GroupPatch)
-  Group.send(:include, RedmineCustomWorkflows::Patches::GroupPatch)
-end
\ No newline at end of file
+# Apply patch
+RedmineExtensions::PatchManager.register_model_patch 'Group',
+  'RedmineCustomWorkflows::Patches::GroupPatch'
\ No newline at end of file
diff --git a/lib/redmine_custom_workflows/patches/issue_patch.rb b/lib/redmine_custom_workflows/patches/issue_patch.rb
index be0f9ae..1ad2a6b 100644
--- a/lib/redmine_custom_workflows/patches/issue_patch.rb
+++ b/lib/redmine_custom_workflows/patches/issue_patch.rb
@@ -24,7 +24,6 @@ module RedmineCustomWorkflows
     module IssuePatch
 
       def self.included(base)
-        base.send(:include, InstanceMethods)
         base.class_eval do
           before_save :before_save_custom_workflows
           after_save :after_save_custom_workflows
@@ -49,8 +48,6 @@ module RedmineCustomWorkflows
         end
       end
 
-      module InstanceMethods
-
         def validate_status
           return true unless @saved_attributes && @saved_attributes['status_id'] != status_id &&
               !new_statuses_allowed_to(User.current, new_record?).collect(&:id).include?(status_id)
@@ -86,12 +83,10 @@ module RedmineCustomWorkflows
           CustomWorkflow.run_custom_workflows(:issue, self, :after_destroy)
         end
 
-      end
-
     end
   end
 end
 
-unless Issue.include?(RedmineCustomWorkflows::Patches::IssuePatch)
-  Issue.send(:include, RedmineCustomWorkflows::Patches::IssuePatch)
-end
\ No newline at end of file
+# Apply patch
+RedmineExtensions::PatchManager.register_model_patch 'Issue',
+  'RedmineCustomWorkflows::Patches::IssuePatch'
\ No newline at end of file
diff --git a/lib/redmine_custom_workflows/patches/mailer_patch.rb b/lib/redmine_custom_workflows/patches/mailer_patch.rb
new file mode 100644
index 0000000..10c9d92
--- /dev/null
+++ b/lib/redmine_custom_workflows/patches/mailer_patch.rb
@@ -0,0 +1,54 @@
+# encoding: utf-8
+#
+# Redmine plugin for Custom Workflows
+#
+# Copyright Anton Argirov
+# Copyright Karel Pičman <karel.picman@kontron.com>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+module RedmineCustomWorkflows
+  module Patches
+    module MailerPatch
+
+      def self.deliver_custom_email(headers={})
+        user = headers.delete :user
+        headers[:to] = user.mail if user
+        text_body = headers.delete :text_body
+        html_body = headers.delete :html_body
+        template_name = headers.delete :template_name
+        template_params = headers.delete(:template_params) || {}
+        if text_body || html_body
+          mail headers do |format|
+            format.text { render :text => text_body } if text_body
+            format.html { render :text => html_body } if html_body
+          end
+        elsif template_name
+          template_params.each { |k,v| instance_variable_set("@#{k}", v) }
+          mail headers do |format|
+            format.text { render template_name }
+            format.html { render template_name } unless Setting.plain_text_mail?
+          end
+        else
+          raise 'Not :text_body, :html_body or :template_name specified'
+        end
+      end
+
+    end
+  end
+end
+
+RedmineExtensions::PatchManager.register_model_patch 'Mailer',
+  'RedmineCustomWorkflows::Patches::MailerPatch'
\ No newline at end of file
diff --git a/lib/redmine_custom_workflows/patches/project_patch.rb b/lib/redmine_custom_workflows/patches/project_patch.rb
index 5bca9b2..93206ba 100644
--- a/lib/redmine_custom_workflows/patches/project_patch.rb
+++ b/lib/redmine_custom_workflows/patches/project_patch.rb
@@ -24,7 +24,6 @@ module RedmineCustomWorkflows
     module ProjectPatch
 
       def self.included(base)
-        base.send :include, InstanceMethods
         base.class_eval do
           has_and_belongs_to_many :custom_workflows
           safe_attributes :custom_workflow_ids, :if =>
@@ -48,37 +47,33 @@ module RedmineCustomWorkflows
         end
       end
 
-      module InstanceMethods
+      def before_save_custom_workflows
+        @project = self
+        @saved_attributes = attributes.dup
+        CustomWorkflow.run_shared_code(self)
+        CustomWorkflow.run_custom_workflows(:project, self, :before_save)
+        throw :abort if errors.any?
+        errors.empty? && (@saved_attributes == attributes || valid?)
+      ensure
+        @saved_attributes = nil
+      end
 
-        def before_save_custom_workflows
-          @project = self
-          @saved_attributes = attributes.dup
-          CustomWorkflow.run_shared_code(self)
-          CustomWorkflow.run_custom_workflows(:project, self, :before_save)
-          throw :abort if errors.any?
-          errors.empty? && (@saved_attributes == attributes || valid?)
-        ensure
-          @saved_attributes = nil
-        end
+      def after_save_custom_workflows
+        CustomWorkflow.run_custom_workflows(:project, self, :after_save)
+      end
 
-        def after_save_custom_workflows
-          CustomWorkflow.run_custom_workflows(:project, self, :after_save)
-        end
-
-        def before_destroy_custom_workflows
-          CustomWorkflow.run_custom_workflows(:project, self, :before_destroy)
-        end
-
-        def after_destroy_custom_workflows
-          CustomWorkflow.run_custom_workflows(:project, self, :after_destroy)
-        end
+      def before_destroy_custom_workflows
+        CustomWorkflow.run_custom_workflows(:project, self, :before_destroy)
+      end
 
+      def after_destroy_custom_workflows
+        CustomWorkflow.run_custom_workflows(:project, self, :after_destroy)
       end
 
     end
   end
 end
 
-unless Project.include?(RedmineCustomWorkflows::Patches::ProjectPatch)
-  Project.send(:include, RedmineCustomWorkflows::Patches::ProjectPatch)
-end
\ No newline at end of file
+# Apply patch
+RedmineExtensions::PatchManager.register_model_patch 'Project',
+  'RedmineCustomWorkflows::Patches::ProjectPatch'
\ No newline at end of file
diff --git a/lib/redmine_custom_workflows/patches/projects_helper_patch.rb b/lib/redmine_custom_workflows/patches/projects_helper_patch.rb
index d3ddc7d..ac353a8 100644
--- a/lib/redmine_custom_workflows/patches/projects_helper_patch.rb
+++ b/lib/redmine_custom_workflows/patches/projects_helper_patch.rb
@@ -34,4 +34,9 @@ module RedmineCustomWorkflows
   end
 end
 
-ProjectsController.send :helper, RedmineCustomWorkflows::Patches::ProjectsHelperPatch
+if Redmine::Plugin.installed?(:easy_extensions)
+  RedmineExtensions::PatchManager.register_helper_patch 'ProjectsHelper',
+    'RedmineCustomWorkflows::Patches::ProjectsHelperPatch', prepend: true
+else
+  ProjectsController.send :helper, RedmineCustomWorkflows::Patches::ProjectsHelperPatch
+end
\ No newline at end of file
diff --git a/lib/redmine_custom_workflows/patches/time_entry_patch.rb b/lib/redmine_custom_workflows/patches/time_entry_patch.rb
index e060caf..563a1ae 100644
--- a/lib/redmine_custom_workflows/patches/time_entry_patch.rb
+++ b/lib/redmine_custom_workflows/patches/time_entry_patch.rb
@@ -24,7 +24,6 @@ module RedmineCustomWorkflows
     module TimeEntryPatch
 
       def self.included(base)
-        base.send(:include, InstanceMethods)
         base.class_eval do
           before_save :before_save_custom_workflows
           after_save :after_save_custom_workflows
@@ -33,37 +32,33 @@ module RedmineCustomWorkflows
         end
       end
 
-      module InstanceMethods
+      def before_save_custom_workflows
+        @time_entry = self
+        @saved_attributes = attributes.dup
+        CustomWorkflow.run_shared_code(self)
+        CustomWorkflow.run_custom_workflows(:time_entry, self, :before_save)
+        throw :abort if errors.any?
+        errors.empty? && (@saved_attributes == attributes || valid?)
+      ensure
+        @saved_attributes = nil
+      end
 
-        def before_save_custom_workflows
-          @time_entry = self
-          @saved_attributes = attributes.dup
-          CustomWorkflow.run_shared_code(self)
-          CustomWorkflow.run_custom_workflows(:time_entry, self, :before_save)
-          throw :abort if errors.any?
-          errors.empty? && (@saved_attributes == attributes || valid?)
-        ensure
-          @saved_attributes = nil
-        end
+      def after_save_custom_workflows
+        CustomWorkflow.run_custom_workflows(:time_entry, self, :after_save)
+      end
 
-        def after_save_custom_workflows
-          CustomWorkflow.run_custom_workflows(:time_entry, self, :after_save)
-        end
-
-        def before_destroy_custom_workflows
-          CustomWorkflow.run_custom_workflows(:time_entry, self, :before_destroy)
-        end
-
-        def after_destroy_custom_workflows
-          CustomWorkflow.run_custom_workflows(:time_entry, self, :after_destroy)
-        end
+      def before_destroy_custom_workflows
+        CustomWorkflow.run_custom_workflows(:time_entry, self, :before_destroy)
+      end
 
+      def after_destroy_custom_workflows
+        CustomWorkflow.run_custom_workflows(:time_entry, self, :after_destroy)
       end
 
     end
   end
 end
 
-unless TimeEntry.include?(RedmineCustomWorkflows::Patches::TimeEntryPatch)
-  TimeEntry.send(:include, RedmineCustomWorkflows::Patches::TimeEntryPatch)
-end
\ No newline at end of file
+# Apply patch
+RedmineExtensions::PatchManager.register_model_patch 'TimeEntry',
+  'RedmineCustomWorkflows::Patches::TimeEntryPatch'
\ No newline at end of file
diff --git a/lib/redmine_custom_workflows/patches/user_patch.rb b/lib/redmine_custom_workflows/patches/user_patch.rb
index 8092029..31934ae 100644
--- a/lib/redmine_custom_workflows/patches/user_patch.rb
+++ b/lib/redmine_custom_workflows/patches/user_patch.rb
@@ -24,7 +24,6 @@ module RedmineCustomWorkflows
     module UserPatch
 
       def self.included(base)
-        base.send(:include, InstanceMethods)
         base.class_eval do
           before_save :before_save_custom_workflows
           after_save :after_save_custom_workflows
@@ -33,37 +32,33 @@ module RedmineCustomWorkflows
         end
       end
 
-      module InstanceMethods
+      def before_save_custom_workflows
+        @user = self
+        @saved_attributes = attributes.dup
+        CustomWorkflow.run_shared_code(self)
+        CustomWorkflow.run_custom_workflows(:user, self, :before_save)
+        throw :abort if errors.any?
+        errors.empty? && (@saved_attributes == attributes || valid?)
+      ensure
+        @saved_attributes = nil
+      end
 
-        def before_save_custom_workflows
-          @user = self
-          @saved_attributes = attributes.dup
-          CustomWorkflow.run_shared_code(self)
-          CustomWorkflow.run_custom_workflows(:user, self, :before_save)
-          throw :abort if errors.any?
-          errors.empty? && (@saved_attributes == attributes || valid?)
-        ensure
-          @saved_attributes = nil
-        end
+      def after_save_custom_workflows
+        CustomWorkflow.run_custom_workflows(:user, self, :after_save)
+      end
 
-        def after_save_custom_workflows
-          CustomWorkflow.run_custom_workflows(:user, self, :after_save)
-        end
-
-        def before_destroy_custom_workflows
-          CustomWorkflow.run_custom_workflows(:user, self, :before_destroy)
-        end
-
-        def after_destroy_custom_workflows
-          CustomWorkflow.run_custom_workflows(:user, self, :after_destroy)
-        end
+      def before_destroy_custom_workflows
+        CustomWorkflow.run_custom_workflows(:user, self, :before_destroy)
+      end
 
+      def after_destroy_custom_workflows
+        CustomWorkflow.run_custom_workflows(:user, self, :after_destroy)
       end
 
     end
   end
 end
 
-unless User.include?(RedmineCustomWorkflows::Patches::UserPatch)
-  User.send(:include, RedmineCustomWorkflows::Patches::UserPatch)
-end
\ No newline at end of file
+# Apply patch
+RedmineExtensions::PatchManager.register_model_patch 'User',
+  'RedmineCustomWorkflows::Patches::UserPatch'
\ No newline at end of file
diff --git a/lib/redmine_custom_workflows/patches/version_patch.rb b/lib/redmine_custom_workflows/patches/version_patch.rb
index 743c92a..9c9e0ed 100644
--- a/lib/redmine_custom_workflows/patches/version_patch.rb
+++ b/lib/redmine_custom_workflows/patches/version_patch.rb
@@ -24,7 +24,6 @@ module RedmineCustomWorkflows
     module VersionPatch
 
       def self.included(base)
-        base.send(:include, InstanceMethods)
         base.class_eval do
           before_save :before_save_custom_workflows
           after_save :after_save_custom_workflows
@@ -33,37 +32,33 @@ module RedmineCustomWorkflows
         end
       end
 
-      module InstanceMethods
+      def before_save_custom_workflows
+        @version = self
+        @saved_attributes = attributes.dup
+        CustomWorkflow.run_shared_code(self)
+        CustomWorkflow.run_custom_workflows(:version, self, :before_save)
+        throw :abort if errors.any?
+        errors.empty? && (@saved_attributes == attributes || valid?)
+      ensure
+        @saved_attributes = nil
+      end
 
-        def before_save_custom_workflows
-          @version = self
-          @saved_attributes = attributes.dup
-          CustomWorkflow.run_shared_code(self)
-          CustomWorkflow.run_custom_workflows(:version, self, :before_save)
-          throw :abort if errors.any?
-          errors.empty? && (@saved_attributes == attributes || valid?)
-        ensure
-          @saved_attributes = nil
-        end
+      def after_save_custom_workflows
+        CustomWorkflow.run_custom_workflows(:version, self, :after_save)
+      end
 
-        def after_save_custom_workflows
-          CustomWorkflow.run_custom_workflows(:version, self, :after_save)
-        end
-
-        def before_destroy_custom_workflows
-          CustomWorkflow.run_custom_workflows(:version, self, :before_destroy)
-        end
-
-        def after_destroy_custom_workflows
-          CustomWorkflow.run_custom_workflows(:version, self, :after_destroy)
-        end
+      def before_destroy_custom_workflows
+        CustomWorkflow.run_custom_workflows(:version, self, :before_destroy)
+      end
 
+      def after_destroy_custom_workflows
+        CustomWorkflow.run_custom_workflows(:version, self, :after_destroy)
       end
 
     end
   end
 end
 
-unless Version.include?(RedmineCustomWorkflows::Patches::VersionPatch)
-  Version.send(:include, RedmineCustomWorkflows::Patches::VersionPatch)
-end
\ No newline at end of file
+# Apply patch
+RedmineExtensions::PatchManager.register_model_patch 'Version',
+'RedmineCustomWorkflows::Patches::VersionPatch'
\ No newline at end of file
diff --git a/lib/redmine_custom_workflows/patches/wiki_content_patch.rb b/lib/redmine_custom_workflows/patches/wiki_content_patch.rb
index 0230032..3b7bfc0 100644
--- a/lib/redmine_custom_workflows/patches/wiki_content_patch.rb
+++ b/lib/redmine_custom_workflows/patches/wiki_content_patch.rb
@@ -24,7 +24,6 @@ module RedmineCustomWorkflows
     module WikiContentPatch
 
       def self.included(base)
-        base.send(:include, InstanceMethods)
         base.class_eval do
           before_save :before_save_custom_workflows
           after_save :after_save_custom_workflows
@@ -33,37 +32,33 @@ module RedmineCustomWorkflows
         end
       end
 
-      module InstanceMethods
+      def before_save_custom_workflows
+        @content = self
+        @saved_attributes = attributes.dup
+        CustomWorkflow.run_shared_code(self)
+        CustomWorkflow.run_custom_workflows(:wiki_content, self, :before_save)
+        throw :abort if errors.any?
+        errors.empty? && (@saved_attributes == attributes || valid?)
+      ensure
+        @saved_attributes = nil
+      end
 
-        def before_save_custom_workflows
-          @content = self
-          @saved_attributes = attributes.dup
-          CustomWorkflow.run_shared_code(self)
-          CustomWorkflow.run_custom_workflows(:wiki_content, self, :before_save)
-          throw :abort if errors.any?
-          errors.empty? && (@saved_attributes == attributes || valid?)
-        ensure
-          @saved_attributes = nil
-        end
+      def after_save_custom_workflows
+        CustomWorkflow.run_custom_workflows(:wiki_content, self, :after_save)
+      end
 
-        def after_save_custom_workflows
-          CustomWorkflow.run_custom_workflows(:wiki_content, self, :after_save)
-        end
-
-        def before_destroy_custom_workflows
-          CustomWorkflow.run_custom_workflows(:wiki_content, self, :before_destroy)
-        end
-
-        def after_destroy_custom_workflows
-          CustomWorkflow.run_custom_workflows(:wiki_content, self, :after_destroy)
-        end
+      def before_destroy_custom_workflows
+        CustomWorkflow.run_custom_workflows(:wiki_content, self, :before_destroy)
+      end
 
+      def after_destroy_custom_workflows
+        CustomWorkflow.run_custom_workflows(:wiki_content, self, :after_destroy)
       end
 
     end
   end
 end
 
-unless WikiContent.include?(RedmineCustomWorkflows::Patches::WikiContentPatch)
-  WikiContent.send(:include, RedmineCustomWorkflows::Patches::WikiContentPatch)
-end
+# Apply patch
+RedmineExtensions::PatchManager.register_model_patch 'WikiContent',
+  'RedmineCustomWorkflows::Patches::WikiContentPatch'
\ No newline at end of file
diff --git a/lib/redmine_custom_workflows/patches/wiki_page_patch.rb b/lib/redmine_custom_workflows/patches/wiki_page_patch.rb
index e560dcc..228bc6b 100644
--- a/lib/redmine_custom_workflows/patches/wiki_page_patch.rb
+++ b/lib/redmine_custom_workflows/patches/wiki_page_patch.rb
@@ -42,6 +42,6 @@ module RedmineCustomWorkflows
   end
 end
 
-unless WikiPage.include?(RedmineCustomWorkflows::Patches::WikiPagePatch)
-  WikiPage.send(:include, RedmineCustomWorkflows::Patches::WikiPagePatch)
-end
+# Apply patch
+RedmineExtensions::PatchManager.register_model_patch 'WikiPage',
+  'RedmineCustomWorkflows::Patches::WikiPagePatch'
\ No newline at end of file