diff --git a/Changelog.md b/CHANGELOG.md
similarity index 83%
rename from Changelog.md
rename to CHANGELOG.md
index d49aa173..31cebb50 100644
--- a/Changelog.md
+++ b/CHANGELOG.md
@@ -2,6 +2,29 @@
 
 All notable changes of the PHP Mode 1.19.1 release series are documented in this file using the [Keep a CHANGELOG](http://keepachangelog.com/) principles.
 
+## [1.21.4] - 2019-05-29
+
+This version contains unobtrusive changes for future compatibility. Also, `forward-page` /` backward-page` may improve your operation. Thank you [@takeokunn].
+
+### Added
+
+ * A new command `php-mode-maybe` has been added to improve the compatibility of Blade templates and HTML templates with Web Mode. ([#532])
+ * A new custom variable php-mode-page-delimiter is added, which is assigned to page-delimiter in PHP-Mode. It allows you to move smoothly to the previous and subsequent definition statements with `forward-page` (<kbd>C-x C-[</kbd>) and `backward-page` (<kbd>C-x C-]</kbd>). ([#540] by [@takeokunn])
+
+### Change
+
+ * `php-maybe-mode` and `.php` files are associated with `auto-mode-alist` instead of `php-mode` ([#532])
+ * Compatibility with [poly-php] has been improved. This has not yet been officially released.
+
+### Deprecated
+
+ * PHP Mode does not support phpt files . Consider installing the [phpt-mode] package. This mode is a wrapper around Polymode based PHP-Mode.
+
+[#532]: https://github.com/emacs-php/php-mode/pull/532
+[#539]: https://github.com/emacs-php/php-mode/pull/539
+[#540]: https://github.com/emacs-php/php-mode/pull/540
+[@takeokunn](https://github.com/takeokunn)
+
 ## [1.21.3] - 2019-05-25
 
 This version includes both PHP syntax support enhancements and performance improvements. See https://github.com/emacs-php/php-mode/projects/1 for all issues for this release.  Also, [@mallt] has helped me improve it with a number of issues. thank you very much.
@@ -153,3 +176,5 @@ See [Changelog · emacs-php/php-mode Wiki](https://github.com/emacs-php/php-mode
 [@mallt]: https://github.com/mallt
 [@sergeyklay]: https://github.com/sergeyklay
 [PHP 7.2 arrow function]: https://wiki.php.net/rfc/arrow_functions_v2
+[poly-php]: https://github.com/emacs-php/poly-php
+[phpt-mode]: https://github.com/emacs-php/phpt-mode
diff --git a/php-face.el b/php-face.el
index a674dd43..75bdc81c 100644
--- a/php-face.el
+++ b/php-face.el
@@ -4,7 +4,7 @@
 
 ;; Author: USAMI Kenta <tadsan@zonu.me>
 ;; Created: 5 May 2019
-;; Version: 1.21.3
+;; Version: 1.21.4
 ;; Keywords: faces, php
 ;; Homepage: https://github.com/emacs-php/php-mode
 ;; Package-Requires: ((emacs "24.3"))
diff --git a/php-mode-debug.el b/php-mode-debug.el
index e5a0229d..0cc09cb1 100644
--- a/php-mode-debug.el
+++ b/php-mode-debug.el
@@ -5,7 +5,7 @@
 ;; Author: USAMI Kenta <tadsan@zonu.me>
 ;; URL: https://github.com/emacs-php/php-mode
 ;; Keywords: maint
-;; Version: 1.21.3
+;; Version: 1.21.4
 ;; Package-Requires: ((emacs "24.3") (cl-lib "0.5"))
 ;; License: GPL-3.0-or-later
 
diff --git a/php-mode.el b/php-mode.el
index 17e4e9f5..a339e17f 100644
--- a/php-mode.el
+++ b/php-mode.el
@@ -9,14 +9,14 @@
 ;; Maintainer: USAMI Kenta <tadsan@zonu.me>
 ;; URL: https://github.com/emacs-php/php-mode
 ;; Keywords: languages php
-;; Version: 1.21.3
+;; Version: 1.21.4
 ;; Package-Requires: ((emacs "24.3") (cl-lib "0.5"))
 ;; License: GPL-3.0-or-later
 
-(defconst php-mode-version-number "1.21.3"
+(defconst php-mode-version-number "1.21.4"
   "PHP Mode version number.")
 
-(defconst php-mode-modified "2019-05-25"
+(defconst php-mode-modified "2019-05-29"
   "PHP Mode build date.")
 
 ;; This program is free software; you can redistribute it and/or modify
@@ -34,32 +34,25 @@
 
 ;;; Commentary:
 
-;; PHP Mode is a major mode for editing PHP source code.  It's an
-;; extension of C mode; thus it inherits all C mode's navigation
-;; functionality.  But it colors according to the PHP grammar and
-;; indents according to the PEAR coding guidelines.  It also includes
-;; a couple handy IDE-type features such as documentation search and a
-;; source and class browser.
+;; PHP Mode is a major mode for editing PHP script.  It's an extension
+;; of CC mode; thus it inherits all C mode's navigation functionality.
+;; But it colors according to the PHP syntax and indents according to the
+;; PSR-2 coding guidelines.  It also includes a couple handy IDE-type
+;; features such as documentation search and a source and class browser.
 
-;; ## Usage
+;; Please read the manual for setting items compatible with CC Mode.
+;; https://www.gnu.org/software/emacs/manual/html_mono/ccmode.html
 
-;; Put this file in your Emacs Lisp path (eg. site-lisp) and add to
-;; your .emacs file:
+;; This mode is designed for PHP scripts consisting of a single <?php block.
+;; We recommend the introduction of Web Mode for HTML and Blade templates combined with PHP.
+;; http://web-mode.org/
 
-;;   (require 'php-mode)
+;; Modern PHP Mode can be set on a project basis by .dir-locals.el.
+;; Please read php-project.el for details of directory local variables.
 
-;; To use abbrev-mode, add lines like this:
-
-;;   (add-hook 'php-mode-hook
-;;     '(lambda () (define-abbrev php-mode-abbrev-table "ex" "extends")))
-
-;; To make php-mode compatible with html-mode, see http://php-mode.sf.net
-
-;; Many options available under Help:Customize
-;; Options specific to php-mode are in
-;;  Programming/Languages/PHP
-;; Since it inherits much functionality from c-mode, look there too
-;;  Programming/Languages/C
+;; If you are using a package manager, you do not need (require 'php-mode) in
+;; your ~/.emacs.d/init.el.  Read the README for installation instructions.
+;; https://github.com/emacs-php/php-mode
 
 ;;; Code:
 
diff --git a/php-project.el b/php-project.el
index 7ab003e2..eb9a50ef 100644
--- a/php-project.el
+++ b/php-project.el
@@ -5,7 +5,7 @@
 ;; Author: USAMI Kenta <tadsan@zonu.me>
 ;; Keywords: tools, files
 ;; URL: https://github.com/emacs-php/php-mode
-;; Version: 1.21.3
+;; Version: 1.21.4
 ;; Package-Requires: ((emacs "24.3") (cl-lib "0.5"))
 ;; License: GPL-3.0-or-later
 
diff --git a/php.el b/php.el
index 13f2cef1..f1e46de9 100644
--- a/php.el
+++ b/php.el
@@ -4,7 +4,7 @@
 
 ;; Author: USAMI Kenta <tadsan@zonu.me>
 ;; Created: 5 Dec 2018
-;; Version: 1.21.3
+;; Version: 1.21.4
 ;; Keywords: languages, php
 ;; Homepage: https://github.com/emacs-php/php-mode
 ;; Package-Requires: ((emacs "24.3") (cl-lib "0.5"))