diff --git a/readme.txt b/readme.txt
index 418c4c16..b92d6013 100644
--- a/readme.txt
+++ b/readme.txt
@@ -2,7 +2,7 @@
 Contributors: takayukister
 Donate link: https://contactform7.com/donate/
 Tags: contact, form, contact form, feedback, email, ajax, captcha, akismet, multilingual
-Requires at least: 5.7
+Requires at least: 5.9
 Tested up to: 5.9
 Stable tag: 5.5.5
 License: GPLv2 or later
@@ -107,16 +107,4 @@ For more information, see [Releases](https://contactform7.com/category/releases/
 
 [https://contactform7.com/contact-form-7-55/](https://contactform7.com/contact-form-7-55/)
 
-= 5.4.2 =
-
-[https://contactform7.com/contact-form-7-542/](https://contactform7.com/contact-form-7-542/)
-
-= 5.4.1 =
-
-[https://contactform7.com/contact-form-7-541/](https://contactform7.com/contact-form-7-541/)
-
-= 5.4 =
-
-[https://contactform7.com/contact-form-7-54/](https://contactform7.com/contact-form-7-54/)
-
 == Upgrade Notice ==
diff --git a/wp-contact-form-7.php b/wp-contact-form-7.php
index 47045094..86ace956 100644
--- a/wp-contact-form-7.php
+++ b/wp-contact-form-7.php
@@ -7,12 +7,12 @@
 Author URI: https://ideasilo.wordpress.com/
 Text Domain: contact-form-7
 Domain Path: /languages/
-Version: 5.5.6
+Version: 5.6-alpha
 */
 
-define( 'WPCF7_VERSION', '5.5.6' );
+define( 'WPCF7_VERSION', '5.6-alpha' );
 
-define( 'WPCF7_REQUIRED_WP_VERSION', '5.7' );
+define( 'WPCF7_REQUIRED_WP_VERSION', '5.9' );
 
 define( 'WPCF7_TEXT_DOMAIN', 'contact-form-7' );