diff --git a/README.md b/README.md
index 71c12fa..0c43374 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,9 @@ Link to Redmine plugin page: https://www.redmine.org/plugins/redmine_issue_todo_
 
 ## Compatibility
 
-* Last tested with Redmine 3.4, should also work with 2.6 - 3.3
+* Version 1.3 for >= Redmine 4 **ONLY**
+* Version 1.2 for <= Redmine 3.4
+* Currently there's no difference between 1.2 and 1.3 except Redmine 4 compatibility
 
 ## Features
 
diff --git a/app/controllers/issue_todo_list_items_controller.rb b/app/controllers/issue_todo_list_items_controller.rb
index 66f9025..44febb1 100644
--- a/app/controllers/issue_todo_list_items_controller.rb
+++ b/app/controllers/issue_todo_list_items_controller.rb
@@ -1,7 +1,7 @@
 class IssueTodoListItemsController < ApplicationController
 
-  before_filter :find_project
-  before_filter :find_todo_list
+  before_action :find_project
+  before_action :find_todo_list
 
   def create
     @item = IssueTodoListItem.new
diff --git a/app/controllers/issue_todo_lists_controller.rb b/app/controllers/issue_todo_lists_controller.rb
index c24d546..969264b 100644
--- a/app/controllers/issue_todo_lists_controller.rb
+++ b/app/controllers/issue_todo_lists_controller.rb
@@ -1,7 +1,7 @@
 class IssueTodoListsController < ApplicationController
 
-  before_filter :find_project, :except => [:bulk_allocate_issues]
-  before_filter :find_todo_list, :only => [:show, :edit, :update, :destroy, :update_item_order, :bulk_allocate_issues]
+  before_action :find_project, :except => [:bulk_allocate_issues]
+  before_action :find_todo_list, :only => [:show, :edit, :update, :destroy, :update_item_order, :bulk_allocate_issues]
 
   def index
     @todo_lists = IssueTodoList.where(project_id: @project.id).order('id')
diff --git a/app/models/issue_todo_list.rb b/app/models/issue_todo_list.rb
index 69ebc64..99959eb 100644
--- a/app/models/issue_todo_list.rb
+++ b/app/models/issue_todo_list.rb
@@ -3,13 +3,7 @@ class IssueTodoList < ActiveRecord::Base
   belongs_to :created_by, :class_name => 'User', :foreign_key => 'created_by'
   belongs_to :last_updated_by, :class_name => 'User', :foreign_key => 'last_updated_by'
 
-  # Rails 3 (Redmine 2) and Rails 4 (Redmine 3)
-  if Gem::Version.new(Rails::VERSION::STRING) >= Gem::Version.new('4.0.0')
-    has_many :issue_todo_list_items, -> { order('position ASC') }, dependent: :destroy
-  else
-    has_many :issue_todo_list_items, dependent: :destroy, :order => 'position ASC'
-  end
-
+  has_many :issue_todo_list_items, -> { order('position ASC') }, dependent: :destroy
   has_many :issues, through: :issue_todo_list_items
 
   validates :title, presence: true
diff --git a/db/migrate/001_create_todo_lists.rb b/db/migrate/001_create_todo_lists.rb
index f866ca9..7b3634d 100644
--- a/db/migrate/001_create_todo_lists.rb
+++ b/db/migrate/001_create_todo_lists.rb
@@ -1,20 +1,5 @@
-class CreateTodoLists < ActiveRecord::Migration
+class CreateTodoLists < ActiveRecord::Migration[4.2]
   def up
-    # Check if migration has already been run
-    version = ::ActiveRecord::Base.connection.select_values(
-        "SELECT version FROM #{::ActiveRecord::Migrator.schema_migrations_table_name} WHERE version='1-issue_todo_lists'"
-    )
-
-    # Plugin directory has been renamed
-    # Delete entry and return because migration adds entry afterwards anyway
-    if version.length != 0
-      execute <<-SQL
-        DELETE FROM #{::ActiveRecord::Migrator.schema_migrations_table_name} WHERE version = '1-issue_todo_lists';
-      SQL
-
-      return
-    end
-
     create_table :issue_todo_lists do |t|
       t.string :project_identifier
       t.string :title
diff --git a/db/migrate/002_remove_closed_issues.rb b/db/migrate/002_remove_closed_issues.rb
index 7365e54..2f7c9f2 100644
--- a/db/migrate/002_remove_closed_issues.rb
+++ b/db/migrate/002_remove_closed_issues.rb
@@ -1,4 +1,4 @@
-class RemoveClosedIssues < ActiveRecord::Migration
+class RemoveClosedIssues < ActiveRecord::Migration[4.2]
   def change
     add_column :issue_todo_lists, :remove_closed_issues, :boolean, :default => false, :null => false
   end
diff --git a/db/migrate/003_project_identifier_to_id.rb b/db/migrate/003_project_identifier_to_id.rb
index 533e96f..6a53d11 100644
--- a/db/migrate/003_project_identifier_to_id.rb
+++ b/db/migrate/003_project_identifier_to_id.rb
@@ -1,4 +1,4 @@
-class ProjectIdentifierToId < ActiveRecord::Migration
+class ProjectIdentifierToId < ActiveRecord::Migration[4.2]
   def up
     add_column :issue_todo_lists, :project_id, :integer, null: true, after: :id
 
diff --git a/db/migrate/004_todo_list_item_comments.rb b/db/migrate/004_todo_list_item_comments.rb
index 5430656..219786c 100644
--- a/db/migrate/004_todo_list_item_comments.rb
+++ b/db/migrate/004_todo_list_item_comments.rb
@@ -1,4 +1,4 @@
-class TodoListItemComments < ActiveRecord::Migration
+class TodoListItemComments < ActiveRecord::Migration[4.2]
   def change
     add_column :issue_todo_list_items, :comment, :text, :after => :issue_id
   end
diff --git a/init.rb b/init.rb
index 362a3d8..3c354f4 100644
--- a/init.rb
+++ b/init.rb
@@ -5,7 +5,7 @@
   name 'Issue To-do Lists Plugin'
   author 'Den'
   description 'Organize issues in to-do lists by manually ordering their priority'
-  version '1.2'
+  version '1.3'
   url 'https://github.com/canidas/redmine_issue_todo_lists'
   author_url 'mailto:dev@den.cx'