diff --git a/composer.lock b/composer.lock
index a0c8b9c22af..c1b46050b45 100644
--- a/composer.lock
+++ b/composer.lock
@@ -491,7 +491,7 @@
         },
         {
             "name": "drupal/core",
-            "version": "10.3.0-beta1",
+            "version": "10.3.x-dev",
             "dist": {
                 "type": "path",
                 "url": "core",
@@ -652,7 +652,7 @@
         },
         {
             "name": "drupal/core-project-message",
-            "version": "10.3.0-beta1",
+            "version": "10.3.x-dev",
             "dist": {
                 "type": "path",
                 "url": "composer/Plugin/ProjectMessage",
@@ -685,7 +685,7 @@
         },
         {
             "name": "drupal/core-vendor-hardening",
-            "version": "10.3.0-beta1",
+            "version": "10.3.x-dev",
             "dist": {
                 "type": "path",
                 "url": "composer/Plugin/VendorHardening",
@@ -9608,7 +9608,11 @@
     ],
     "aliases": [],
     "minimum-stability": "dev",
-    "stability-flags": [],
+    "stability-flags": {
+        "drupal/core": 20,
+        "drupal/core-project-message": 20,
+        "drupal/core-vendor-hardening": 20
+    },
     "prefer-stable": true,
     "prefer-lowest": false,
     "platform": [],
diff --git a/composer/Metapackage/CoreRecommended/composer.json b/composer/Metapackage/CoreRecommended/composer.json
index 48ea13088a9..d47a031ae37 100644
--- a/composer/Metapackage/CoreRecommended/composer.json
+++ b/composer/Metapackage/CoreRecommended/composer.json
@@ -7,7 +7,7 @@
         "webflo/drupal-core-strict": "*"
     },
     "require": {
-        "drupal/core": "10.3.0-beta1",
+        "drupal/core": "10.3.x-dev",
         "asm89/stack-cors": "~v2.2.0",
         "composer/semver": "~3.4.0",
         "doctrine/annotations": "~1.14.3",
diff --git a/composer/Metapackage/PinnedDevDependencies/composer.json b/composer/Metapackage/PinnedDevDependencies/composer.json
index 58768cbb946..b75a06197de 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": "10.3.0-beta1",
+        "drupal/core": "10.3.x-dev",
         "behat/mink": "v1.11.0",
         "behat/mink-browserkit-driver": "v2.2.0",
         "colinodell/psr-testlogger": "v1.3.0",
diff --git a/composer/Template/LegacyProject/composer.json b/composer/Template/LegacyProject/composer.json
index b74c32b8c5e..da3bb1a0cb1 100644
--- a/composer/Template/LegacyProject/composer.json
+++ b/composer/Template/LegacyProject/composer.json
@@ -27,7 +27,7 @@
     "conflict": {
         "drupal/drupal": "*"
     },
-    "minimum-stability": "beta",
+    "minimum-stability": "dev",
     "prefer-stable": true,
     "config": {
         "allow-plugins": {
diff --git a/composer/Template/RecommendedProject/composer.json b/composer/Template/RecommendedProject/composer.json
index b89b65a9e05..4814912141e 100644
--- a/composer/Template/RecommendedProject/composer.json
+++ b/composer/Template/RecommendedProject/composer.json
@@ -26,7 +26,7 @@
     "conflict": {
         "drupal/drupal": "*"
     },
-    "minimum-stability": "beta",
+    "minimum-stability": "dev",
     "prefer-stable": true,
     "config": {
         "allow-plugins": {
diff --git a/core/lib/Drupal.php b/core/lib/Drupal.php
index ea4fcf1c8d5..4ca937b6c68 100644
--- a/core/lib/Drupal.php
+++ b/core/lib/Drupal.php
@@ -75,7 +75,7 @@ class Drupal {
   /**
    * The current system version.
    */
-  const VERSION = '10.3.0-beta1';
+  const VERSION = '10.3.0-dev';
 
   /**
    * Core API compatibility.
diff --git a/core/lib/Drupal/Component/Annotation/composer.json b/core/lib/Drupal/Component/Annotation/composer.json
index 265c68daedf..218e7b2fa8e 100644
--- a/core/lib/Drupal/Component/Annotation/composer.json
+++ b/core/lib/Drupal/Component/Annotation/composer.json
@@ -9,10 +9,10 @@
     "require": {
         "php": ">=8.1.0",
         "doctrine/annotations": "^1.14",
-        "drupal/core-class-finder": "10.3.0-beta1",
-        "drupal/core-file-cache": "10.3.0-beta1",
-        "drupal/core-plugin": "10.3.0-beta1",
-        "drupal/core-utility": "10.3.0-beta1"
+        "drupal/core-class-finder": "10.3.x-dev",
+        "drupal/core-file-cache": "10.3.x-dev",
+        "drupal/core-plugin": "10.3.x-dev",
+        "drupal/core-utility": "10.3.x-dev"
     },
     "autoload": {
         "psr-4": {
@@ -24,5 +24,5 @@
             "This file was partially generated automatically. See: https://www.drupal.org/node/3293830"
         ]
     },
-    "minimum-stability": "beta"
+    "minimum-stability": "dev"
 }
diff --git a/core/lib/Drupal/Component/Datetime/composer.json b/core/lib/Drupal/Component/Datetime/composer.json
index 14be6bf47e6..c2391fb45a9 100644
--- a/core/lib/Drupal/Component/Datetime/composer.json
+++ b/core/lib/Drupal/Component/Datetime/composer.json
@@ -8,7 +8,7 @@
     "license": "GPL-2.0-or-later",
     "require": {
         "php": ">=8.1.0",
-        "drupal/core-utility": "10.3.0-beta1"
+        "drupal/core-utility": "10.3.x-dev"
     },
     "autoload": {
         "psr-4": {
@@ -20,5 +20,5 @@
             "This file was partially generated automatically. See: https://www.drupal.org/node/3293830"
         ]
     },
-    "minimum-stability": "beta"
+    "minimum-stability": "dev"
 }
diff --git a/core/lib/Drupal/Component/Discovery/composer.json b/core/lib/Drupal/Component/Discovery/composer.json
index a9c4d92fa27..758aef63450 100644
--- a/core/lib/Drupal/Component/Discovery/composer.json
+++ b/core/lib/Drupal/Component/Discovery/composer.json
@@ -8,8 +8,8 @@
     "license": "GPL-2.0-or-later",
     "require": {
         "php": ">=8.1.0",
-        "drupal/core-file-cache": "10.3.0-beta1",
-        "drupal/core-serialization": "10.3.0-beta1"
+        "drupal/core-file-cache": "10.3.x-dev",
+        "drupal/core-serialization": "10.3.x-dev"
     },
     "autoload": {
         "psr-4": {
@@ -21,5 +21,5 @@
             "This file was partially generated automatically. See: https://www.drupal.org/node/3293830"
         ]
     },
-    "minimum-stability": "beta"
+    "minimum-stability": "dev"
 }
diff --git a/core/lib/Drupal/Component/FrontMatter/composer.json b/core/lib/Drupal/Component/FrontMatter/composer.json
index 011dc799699..5ff2dc304eb 100644
--- a/core/lib/Drupal/Component/FrontMatter/composer.json
+++ b/core/lib/Drupal/Component/FrontMatter/composer.json
@@ -8,7 +8,7 @@
     "license": "GPL-2.0-or-later",
     "require": {
         "php": ">=8.1.0",
-        "drupal/core-serialization": "10.3.0-beta1"
+        "drupal/core-serialization": "10.3.x-dev"
     },
     "autoload": {
         "psr-4": {
@@ -20,5 +20,5 @@
             "This file was partially generated automatically. See: https://www.drupal.org/node/3293830"
         ]
     },
-    "minimum-stability": "beta"
+    "minimum-stability": "dev"
 }
diff --git a/core/lib/Drupal/Component/Gettext/composer.json b/core/lib/Drupal/Component/Gettext/composer.json
index dab3bd8c8f8..61f29702297 100644
--- a/core/lib/Drupal/Component/Gettext/composer.json
+++ b/core/lib/Drupal/Component/Gettext/composer.json
@@ -9,7 +9,7 @@
     },
     "require": {
         "php": ">=8.1.0",
-        "drupal/core-render": "10.3.0-beta1"
+        "drupal/core-render": "10.3.x-dev"
     },
     "autoload": {
         "psr-4": {
@@ -21,5 +21,5 @@
             "This file was partially generated automatically. See: https://www.drupal.org/node/3293830"
         ]
     },
-    "minimum-stability": "beta"
+    "minimum-stability": "dev"
 }
diff --git a/core/lib/Drupal/Component/PhpStorage/composer.json b/core/lib/Drupal/Component/PhpStorage/composer.json
index e78f783bc4b..be4099a3367 100644
--- a/core/lib/Drupal/Component/PhpStorage/composer.json
+++ b/core/lib/Drupal/Component/PhpStorage/composer.json
@@ -8,7 +8,7 @@
     "license": "GPL-2.0-or-later",
     "require": {
         "php": ">=8.1.0",
-        "drupal/core-file-security": "10.3.0-beta1"
+        "drupal/core-file-security": "10.3.x-dev"
     },
     "autoload": {
         "psr-4": {
@@ -20,5 +20,5 @@
             "This file was partially generated automatically. See: https://www.drupal.org/node/3293830"
         ]
     },
-    "minimum-stability": "beta"
+    "minimum-stability": "dev"
 }
diff --git a/core/lib/Drupal/Component/Render/composer.json b/core/lib/Drupal/Component/Render/composer.json
index aeb57f55c66..5b2d7738f0c 100644
--- a/core/lib/Drupal/Component/Render/composer.json
+++ b/core/lib/Drupal/Component/Render/composer.json
@@ -8,7 +8,7 @@
     "license": "GPL-2.0-or-later",
     "require": {
         "php": ">=8.1.0",
-        "drupal/core-utility": "10.3.0-beta1"
+        "drupal/core-utility": "10.3.x-dev"
     },
     "autoload": {
         "psr-4": {
@@ -20,5 +20,5 @@
             "This file was partially generated automatically. See: https://www.drupal.org/node/3293830"
         ]
     },
-    "minimum-stability": "beta"
+    "minimum-stability": "dev"
 }