diff --git a/AUTHORS.md b/AUTHORS.md
index 2c25aaee..6aceea50 100644
--- a/AUTHORS.md
+++ b/AUTHORS.md
@@ -84,6 +84,7 @@ Names Sorted Alphabetically:
 - Norio Suzuki
 - Olaf The Viking
 - Peter Oliver
+- Phil Sainty
 - Philippe Ivaldi
 - Piotr Kwiecinski
 - Rex McMaster
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2408957b..1aa2e9cc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,35 @@ All notable changes of the PHP Mode 1.19.1 release series are documented in this
 
 <!-- ## Unreleased -->
 
+## [1.27.0] - 2024-12-20
+
+### Added
+
+ * Support PHP 8.4 property-hooks ([#797])
+
+### Changed
+
+ * Improve `php-syntax-propertize-extend-region` efficiency ([#789], thanks [@phil-s]!)
+ * Update `php-phpdoc-type-names` to support [PHPStan 2.0.4] ([#795])
+
+### Fixed
+
+ * Fix Emacs 30 byte-compile errors ([#792])
+ * Use `when-let*` instead of `when-let` to enhance Emacs 30 compatibility ([#796])
+
+### Removed
+
+ * Drop support for Emacs 26 ([#788])
+
+[@phil-s]: https://github.com/phil-s
+[PHPStan 2.0.4]: https://github.com/phpstan/phpstan/releases/tag/2.0.4
+[#788]: https://github.com/emacs-php/php-mode/pull/788
+[#789]: https://github.com/emacs-php/php-mode/pull/789
+[#792]: https://github.com/emacs-php/php-mode/pull/792
+[#795]: https://github.com/emacs-php/php-mode/pull/795
+[#796]: https://github.com/emacs-php/php-mode/pull/796
+[#797]: https://github.com/emacs-php/php-mode/pull/797
+
 ## [1.26.1] - 2024-09-13
 
 ### Added
diff --git a/README.ja.md b/README.ja.md
index a4af81d9..f9312302 100644
--- a/README.ja.md
+++ b/README.ja.md
@@ -1,8 +1,8 @@
 <div align="center">
   <h1>Emacs PHP Mode</h1>
 
-[![Emacs: 29.4](https://img.shields.io/badge/Emacs-29.4-blue.svg)](https://www.gnu.org/software/emacs/)
-[![lang: PHP 8.3](https://img.shields.io/badge/lang-PHP%208.3-brightgreen.svg)](https://php.net/manual/migration83.php)
+[![Emacs: 30.0](https://img.shields.io/badge/Emacs-30.0-blue.svg)](https://www.gnu.org/software/emacs/)
+[![lang: PHP 8.4](https://img.shields.io/badge/lang-PHP%208.4-brightgreen.svg)](https://www.php.net/releases/8.4/)
 [![Build Status](https://github.com/emacs-php/php-mode/workflows/CI/badge.svg)](https://github.com/emacs-php/php-mode/actions)
 [![GPL v3](https://img.shields.io/badge/license-GPL_v3-green.svg)][gpl-v3]<br>
 [![NonGNU ELPA][nongnu-elpa-badge]][nongnu-elpa]
@@ -17,10 +17,15 @@ A powerful and flexible Emacs major mode for editing PHP scripts
 [GitHubプロジェクト][php-mode]にissueを作成してバグ報告や機能リクエストを送ってください。
 
 > [!NOTE]
-> [最新版][releases]のPHP ModeはEmacs 29をサポートしています。<br />アップグレードに伴うトラブルは[Discussions][disscussions-emacs29]に気軽に書き込んでください。
+> [最新版][releases]のPHP ModeはEmacs 30をサポートしています。<br />アップグレードに伴うトラブルは[Discussions][disscussions-emacs30]に気軽に書き込んでください。
+
+> [!WARNING]
+> Emacsをアップグレードした直後に初めてPHPファイルを開いたときに、CC Mode関連のエラーが発生する可能性があります。これは以前のバージョンのEmacsでバイトコンパイルされたPHP Modeがディスクにキャッシュされているために起こるので、PHP Modeの再インストールによって解決します。
+>
+> **`M-x php-mode-debug-reinstall`** または **`M-x package-reinstall php-mode`** コマンドをお試しください。
 
 [releases]: https://github.com/emacs-php/php-mode/releases
-[disscussions-emacs29]: https://github.com/emacs-php/php-mode/discussions/751
+[disscussions-emacs30]: https://github.com/emacs-php/php-mode/discussions/798
 
 ## インストール
 
diff --git a/README.md b/README.md
index f546d25a..8ba8a04b 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,8 @@
 <div align="center">
   <h1>Emacs PHP Mode</h1>
 
-[![Emacs: 29.4](https://img.shields.io/badge/Emacs-29.4-blue.svg)](https://www.gnu.org/software/emacs/)
-[![lang: PHP 8.3](https://img.shields.io/badge/lang-PHP%208.3-brightgreen.svg)](https://www.php.net/manual/migration83.php)
+[![Emacs: 30.0](https://img.shields.io/badge/Emacs-30.0-blue.svg)](https://www.gnu.org/software/emacs/)
+[![lang: PHP 8.4](https://img.shields.io/badge/lang-PHP%208.4-brightgreen.svg)](https://www.php.net/releases/8.4/)
 [![Build Status](https://github.com/emacs-php/php-mode/workflows/CI/badge.svg)](https://github.com/emacs-php/php-mode/actions)
 [![GPL v3](https://img.shields.io/badge/license-GPL_v3-green.svg)][gpl-v3]<br>
 [![NonGNU ELPA][nongnu-elpa-badge]][nongnu-elpa]
@@ -17,10 +17,15 @@ English &nbsp;&nbsp;|&nbsp;&nbsp; [日本語](README.ja.md)
 Please submit any bug reports or feature requests by creating issues on [the GitHub page for PHP Mode][php-mode].
 
 > [!NOTE]
-> The [latest version][releases] of PHP Mode supports Emacs 29. <br />Please feel free to [write to disucuss][disscussions-emacs29] if you have problems upgrading to Emacs 29.
+> The [latest version][releases] of PHP Mode supports Emacs 30. <br />Please feel free to [write to disucuss][disscussions-emacs30] if you have problems upgrading to Emacs 29.
+
+> [!WARNING]
+> After upgrading Emacs, when you open a PHP file for the first time, you may encounter errors related to CC Mode. These errors occur because a previously byte-compiled version of PHP Mode, cached on your disk, differs from the newly installed one. Reinstalling PHP Mode should resolve the issue.
+>
+> Try running **`M-x php-mode-debug-reinstall`** or **`M-x package-reinstall php-mode`**.
 
 [releases]: https://github.com/emacs-php/php-mode/releases
-[disscussions-emacs29]: https://github.com/emacs-php/php-mode/discussions/751
+[disscussions-emacs30]: https://github.com/emacs-php/php-mode/discussions/798
 
 ## Installation