diff --git a/gutenberg.php b/gutenberg.php
index dbf58c000a107f..9c9e324756258d 100644
--- a/gutenberg.php
+++ b/gutenberg.php
@@ -5,7 +5,7 @@
  * Description: Printing since 1440. This is the development plugin for the block editor, site editor, and other future WordPress core functionality.
  * Requires at least: 6.1
  * Requires PHP: 5.6
- * Version: 15.8.1
+ * Version: 15.9.0-rc.1
  * Author: Gutenberg Team
  * Text Domain: gutenberg
  *
diff --git a/package-lock.json b/package-lock.json
index 2f674821f32951..9a9358f11a53fa 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
 	"name": "gutenberg",
-	"version": "15.8.1",
+	"version": "15.9.0-rc.1",
 	"lockfileVersion": 1,
 	"requires": true,
 	"dependencies": {
diff --git a/package.json b/package.json
index 68ddbe3a056124..b53e6c3505eb6e 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "gutenberg",
-	"version": "15.8.1",
+	"version": "15.9.0-rc.1",
 	"private": true,
 	"description": "A new WordPress editor experience.",
 	"author": "The WordPress Contributors",