diff --git a/package.json b/package.json
index 5bebc4a5d4..05d4ae9cfc 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "WordPress",
-  "version": "4.0.19",
+  "version": "4.0.20",
   "description": "WordPress is web software you can use to create a beautiful website or blog.",
   "repository": {
     "type": "svn",
diff --git a/src/wp-admin/about.php b/src/wp-admin/about.php
index 6cdc444695..a08d1f08f4 100644
--- a/src/wp-admin/about.php
+++ b/src/wp-admin/about.php
@@ -42,7 +42,10 @@ include( ABSPATH . 'wp-admin/admin-header.php' );
 </h2>
 
 <div class="changelog point-releases">
-	<h3><?php echo _n( 'Maintenance and Security Release', 'Maintenance and Security Releases', 19 ); ?></h3>
+	<h3><?php echo _n( 'Maintenance and Security Release', 'Maintenance and Security Releases', 20 ); ?></h3>
+	<p><?php printf( __( '<strong>Version %s</strong> addressed one security issue.' ), '4.0.20' ); ?>
+		<?php printf( __( 'For more information, see <a href="%s">the release notes</a>.' ), 'https://codex.wordpress.org/Version_4.0.20' ); ?>
+	</p>
 	<p><?php printf( _n( '<strong>Version %1$s</strong> addressed a security issue.',
 			'<strong>Version %1$s</strong> addressed some security issues.', 8 ), '4.0.19' ); ?>
 		<?php printf( __( 'For more information, see <a href="%s">the release notes</a>.' ), 'https://codex.wordpress.org/Version_4.0.19' ); ?>
diff --git a/src/wp-includes/version.php b/src/wp-includes/version.php
index 14cddbb739..b69c4dcf2a 100644
--- a/src/wp-includes/version.php
+++ b/src/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.0.19-src';
+$wp_version = '4.0.20-src';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.