diff --git a/CHANGELOG.prerelease.md b/CHANGELOG.prerelease.md
index bfd6341e785..9db0736a9b3 100644
--- a/CHANGELOG.prerelease.md
+++ b/CHANGELOG.prerelease.md
@@ -1,3 +1,15 @@
+## 8.5.0-alpha.21
+
+- Addon A11y: Add typesVersions support for TypeScript definitions in a11y package - [#30005](https://github.com/storybookjs/storybook/pull/30005), thanks @valentinpalkovic!
+- Addon A11y: Refactor environment variable handling for Vitest integration - [#30022](https://github.com/storybookjs/storybook/pull/30022), thanks @valentinpalkovic!
+- Addon A11y: Run the a11y automigration on postInstall - [#30004](https://github.com/storybookjs/storybook/pull/30004), thanks @kasperpeulen!
+- Addon A11y: Update accessibility status handling in TestProviderRender - [#30027](https://github.com/storybookjs/storybook/pull/30027), thanks @valentinpalkovic!
+- Addon Onboarding: Prebundle react-confetti - [#29996](https://github.com/storybookjs/storybook/pull/29996), thanks @yannbf!
+- Addon Test: Show sub test provider toggle state in main testing module - [#30019](https://github.com/storybookjs/storybook/pull/30019), thanks @ghengeveld!
+- Core: Fix bundling of React - [#30003](https://github.com/storybookjs/storybook/pull/30003), thanks @yannbf!
+- TestAddon: Wrap sub-paths exported with `require.resolve` - [#30026](https://github.com/storybookjs/storybook/pull/30026), thanks @ndelangen!
+- Vitest: Correctly stop Storybook when Vitest closes - [#30012](https://github.com/storybookjs/storybook/pull/30012), thanks @JReinhold!
+
 ## 8.5.0-alpha.20
 
 - Addon Test: Add `@vitest/coverage-v8` during postinstall if no coverage reporter is installed - [#29993](https://github.com/storybookjs/storybook/pull/29993), thanks @ghengeveld!
diff --git a/code/package.json b/code/package.json
index 35bc57478fb..15db17f6e90 100644
--- a/code/package.json
+++ b/code/package.json
@@ -294,5 +294,6 @@
         "Dependency Upgrades"
       ]
     ]
-  }
+  },
+  "deferredNextVersion": "8.5.0-alpha.21"
 }
diff --git a/docs/versions/next.json b/docs/versions/next.json
index 2406504741a..ecc54ce4a45 100644
--- a/docs/versions/next.json
+++ b/docs/versions/next.json
@@ -1 +1 @@
-{"version":"8.5.0-alpha.20","info":{"plain":"- Addon Test: Add `@vitest/coverage-v8` during postinstall if no coverage reporter is installed - [#29993](https://github.com/storybookjs/storybook/pull/29993), thanks @ghengeveld!\n- Addon Test: Add support for previewHead - [#29808](https://github.com/storybookjs/storybook/pull/29808), thanks @ndelangen!\n- Addon Test: Always run Vitest in watch mode internally - [#29749](https://github.com/storybookjs/storybook/pull/29749), thanks @JReinhold!\n- Addon Test: Filter out falsy test results in TestProviderRender - [#30001](https://github.com/storybookjs/storybook/pull/30001), thanks @valentinpalkovic!\n- Addon Test: Handle undefined storyId - [#29998](https://github.com/storybookjs/storybook/pull/29998), thanks @ghengeveld!\n- Addon Test: Make component tests status row link to the story's tests panel - [#29992](https://github.com/storybookjs/storybook/pull/29992), thanks @ghengeveld!\n- Addon Test: Merge viteFinal config into vitest config - [#29806](https://github.com/storybookjs/storybook/pull/29806), thanks @ndelangen!\n- Addon Test: Prompt switch to `experimental-nextjs-vite` - [#29814](https://github.com/storybookjs/storybook/pull/29814), thanks @ndelangen!\n- Addon Test: Use ProgressSpinner for stop button in Testing Module - [#29997](https://github.com/storybookjs/storybook/pull/29997), thanks @ghengeveld!"}}
+{"version":"8.5.0-alpha.21","info":{"plain":"- Addon A11y: Add typesVersions support for TypeScript definitions in a11y package - [#30005](https://github.com/storybookjs/storybook/pull/30005), thanks @valentinpalkovic!\n- Addon A11y: Refactor environment variable handling for Vitest integration - [#30022](https://github.com/storybookjs/storybook/pull/30022), thanks @valentinpalkovic!\n- Addon A11y: Run the a11y automigration on postInstall - [#30004](https://github.com/storybookjs/storybook/pull/30004), thanks @kasperpeulen!\n- Addon A11y: Update accessibility status handling in TestProviderRender - [#30027](https://github.com/storybookjs/storybook/pull/30027), thanks @valentinpalkovic!\n- Addon Onboarding: Prebundle react-confetti - [#29996](https://github.com/storybookjs/storybook/pull/29996), thanks @yannbf!\n- Addon Test: Show sub test provider toggle state in main testing module - [#30019](https://github.com/storybookjs/storybook/pull/30019), thanks @ghengeveld!\n- Core: Fix bundling of React - [#30003](https://github.com/storybookjs/storybook/pull/30003), thanks @yannbf!\n- TestAddon: Wrap sub-paths exported with `require.resolve` - [#30026](https://github.com/storybookjs/storybook/pull/30026), thanks @ndelangen!\n- Vitest: Correctly stop Storybook when Vitest closes - [#30012](https://github.com/storybookjs/storybook/pull/30012), thanks @JReinhold!"}}