diff --git a/package.json b/package.json
index dc7ac67627f..b7765a176ae 100644
--- a/package.json
+++ b/package.json
@@ -83,7 +83,7 @@
     "typescript": "^4.2.4"
   },
   "yoast": {
-    "pluginVersion": "21.5"
+    "pluginVersion": "21.6-RC1"
   },
   "version": "0.0.0"
 }
diff --git a/wp-seo-main.php b/wp-seo-main.php
index 3507cfb49e4..18a098a2431 100644
--- a/wp-seo-main.php
+++ b/wp-seo-main.php
@@ -15,7 +15,7 @@
  * {@internal Nobody should be able to overrule the real version number as this can cause
  *            serious issues with the options, so no if ( ! defined() ).}}
  */
-define( 'WPSEO_VERSION', '21.5' );
+define( 'WPSEO_VERSION', '21.6-RC1' );
 
 
 if ( ! defined( 'WPSEO_PATH' ) ) {
diff --git a/wp-seo.php b/wp-seo.php
index 13cbd25029b..c4b15abd7f8 100644
--- a/wp-seo.php
+++ b/wp-seo.php
@@ -8,7 +8,7 @@
  *
  * @wordpress-plugin
  * Plugin Name: Yoast SEO
- * Version:     21.5
+ * Version:     21.6-RC1
  * Plugin URI:  https://yoa.st/1uj
  * Description: The first true all-in-one SEO solution for WordPress, including on-page content analysis, XML sitemaps and much more.
  * Author:      Team Yoast