diff --git a/composer.lock b/composer.lock
index 20656bd4f99b2b2d0442e9470bfd3bbb9a3eaed5..54e36436da90d55ba544f3d2c9e8ffee526454a9 100644
--- a/composer.lock
+++ b/composer.lock
@@ -649,7 +649,7 @@
         },
         {
             "name": "drupal/core",
-            "version": "8.9.x-dev",
+            "version": "8.9.0-beta1",
             "dist": {
                 "type": "path",
                 "url": "core",
@@ -880,7 +880,7 @@
         },
         {
             "name": "drupal/core-project-message",
-            "version": "8.9.x-dev",
+            "version": "8.9.0-beta1",
             "dist": {
                 "type": "path",
                 "url": "composer/Plugin/ProjectMessage",
@@ -910,7 +910,7 @@
         },
         {
             "name": "drupal/core-vendor-hardening",
-            "version": "8.9.x-dev",
+            "version": "8.9.0-beta1",
             "dist": {
                 "type": "path",
                 "url": "composer/Plugin/VendorHardening",
@@ -6452,11 +6452,7 @@
     ],
     "aliases": [],
     "minimum-stability": "dev",
-    "stability-flags": {
-        "drupal/core": 20,
-        "drupal/core-project-message": 20,
-        "drupal/core-vendor-hardening": 20
-    },
+    "stability-flags": [],
     "prefer-stable": true,
     "prefer-lowest": false,
     "platform": [],
diff --git a/composer/Metapackage/CoreRecommended/composer.json b/composer/Metapackage/CoreRecommended/composer.json
index 7aa00552f314466e8de556ed2ef16887c05ce49d..14087a6cbbc438af58085d7d0aa2324bbb8983d0 100644
--- a/composer/Metapackage/CoreRecommended/composer.json
+++ b/composer/Metapackage/CoreRecommended/composer.json
@@ -7,7 +7,7 @@
         "webflo/drupal-core-strict": "*"
     },
     "require": {
-        "drupal/core": "8.9.x-dev",
+        "drupal/core": "8.9.0-beta1",
         "asm89/stack-cors": "1.2.0",
         "composer/installers": "v1.7.0",
         "composer/semver": "1.5.0",
diff --git a/composer/Metapackage/PinnedDevDependencies/composer.json b/composer/Metapackage/PinnedDevDependencies/composer.json
index e3b807e4d061a592635904c2faf06fe09a24f2dd..043e4039d6135fed9416ea860812fca293b7218d 100644
--- a/composer/Metapackage/PinnedDevDependencies/composer.json
+++ b/composer/Metapackage/PinnedDevDependencies/composer.json
@@ -7,7 +7,7 @@
         "webflo/drupal-core-require-dev": "*"
     },
     "require": {
-        "drupal/core": "8.9.x-dev",
+        "drupal/core": "8.9.0-beta1",
         "behat/mink": "v1.8.1",
         "behat/mink-browserkit-driver": "1.3.3",
         "behat/mink-goutte-driver": "v1.2.1",
diff --git a/core/lib/Drupal.php b/core/lib/Drupal.php
index 58c0c7f2f367ffcf33e4ed9b32ddfccdfb7e1a05..fcc7fa1d75946ecb9e369eb2a5c9bc470dbd8fb5 100644
--- a/core/lib/Drupal.php
+++ b/core/lib/Drupal.php
@@ -82,7 +82,7 @@ class Drupal {
   /**
    * The current system version.
    */
-  const VERSION = '8.9.0-dev';
+  const VERSION = '8.9.0-beta1';
 
   /**
    * Core API compatibility.