diff --git a/MIGRATION.md b/MIGRATION.md
index 2e2e735fb21f..b78057b981d3 100644
--- a/MIGRATION.md
+++ b/MIGRATION.md
@@ -1,5 +1,7 @@
 <h1>Migration</h1>
 
+- [From version 8.4.x to 8.5.x](#from-version-84x-to-85x)
+  - [Indexing behavior of @storybook/experimental-addon-test is changed](#indexing-behavior-of-storybookexperimental-addon-test-is-changed)
 - [From version 8.2.x to 8.3.x](#from-version-82x-to-83x)
   - [Removed `experimental_SIDEBAR_BOTTOM` and deprecated `experimental_SIDEBAR_TOP` addon types](#removed-experimental_sidebar_bottom-and-deprecated-experimental_sidebar_top-addon-types)
   - [New parameters format for addon backgrounds](#new-parameters-format-for-addon-backgrounds)
@@ -105,17 +107,17 @@
     - [Tab addons cannot manually route, Tool addons can filter their visibility via tabId](#tab-addons-cannot-manually-route-tool-addons-can-filter-their-visibility-via-tabid)
     - [Removed `config` preset](#removed-config-preset-1)
 - [From version 7.5.0 to 7.6.0](#from-version-750-to-760)
-  - [CommonJS with Vite is deprecated](#commonjs-with-vite-is-deprecated)
-  - [Using implicit actions during rendering is deprecated](#using-implicit-actions-during-rendering-is-deprecated)
-  - [typescript.skipBabel deprecated](#typescriptskipbabel-deprecated)
-  - [Primary doc block accepts of prop](#primary-doc-block-accepts-of-prop)
-  - [Addons no longer need a peer dependency on React](#addons-no-longer-need-a-peer-dependency-on-react)
+    - [CommonJS with Vite is deprecated](#commonjs-with-vite-is-deprecated)
+    - [Using implicit actions during rendering is deprecated](#using-implicit-actions-during-rendering-is-deprecated)
+    - [typescript.skipBabel deprecated](#typescriptskipbabel-deprecated)
+    - [Primary doc block accepts of prop](#primary-doc-block-accepts-of-prop)
+    - [Addons no longer need a peer dependency on React](#addons-no-longer-need-a-peer-dependency-on-react)
 - [From version 7.4.0 to 7.5.0](#from-version-740-to-750)
-  - [`storyStoreV6` and `storiesOf` is deprecated](#storystorev6-and-storiesof-is-deprecated)
-  - [`storyIndexers` is replaced with `experimental_indexers`](#storyindexers-is-replaced-with-experimental_indexers)
+    - [`storyStoreV6` and `storiesOf` is deprecated](#storystorev6-and-storiesof-is-deprecated)
+    - [`storyIndexers` is replaced with `experimental_indexers`](#storyindexers-is-replaced-with-experimental_indexers)
 - [From version 7.0.0 to 7.2.0](#from-version-700-to-720)
-  - [Addon API is more type-strict](#addon-api-is-more-type-strict)
-  - [Addon-controls hideNoControlsWarning parameter is deprecated](#addon-controls-hidenocontrolswarning-parameter-is-deprecated)
+    - [Addon API is more type-strict](#addon-api-is-more-type-strict)
+    - [Addon-controls hideNoControlsWarning parameter is deprecated](#addon-controls-hidenocontrolswarning-parameter-is-deprecated)
 - [From version 6.5.x to 7.0.0](#from-version-65x-to-700)
   - [7.0 breaking changes](#70-breaking-changes)
     - [Dropped support for Node 15 and below](#dropped-support-for-node-15-and-below)
@@ -141,7 +143,7 @@
     - [Deploying build artifacts](#deploying-build-artifacts)
       - [Dropped support for file URLs](#dropped-support-for-file-urls)
       - [Serving with nginx](#serving-with-nginx)
-      - [Ignore story files from node_modules](#ignore-story-files-from-node_modules)
+      - [Ignore story files from node\_modules](#ignore-story-files-from-node_modules)
   - [7.0 Core changes](#70-core-changes)
     - [7.0 feature flags removed](#70-feature-flags-removed)
     - [Story context is prepared before for supporting fine grained updates](#story-context-is-prepared-before-for-supporting-fine-grained-updates)
@@ -155,7 +157,7 @@
     - [Addon-interactions: Interactions debugger is now default](#addon-interactions-interactions-debugger-is-now-default)
   - [7.0 Vite changes](#70-vite-changes)
     - [Vite builder uses Vite config automatically](#vite-builder-uses-vite-config-automatically)
-    - [Vite cache moved to node_modules/.cache/.vite-storybook](#vite-cache-moved-to-node_modulescachevite-storybook)
+    - [Vite cache moved to node\_modules/.cache/.vite-storybook](#vite-cache-moved-to-node_modulescachevite-storybook)
   - [7.0 Webpack changes](#70-webpack-changes)
     - [Webpack4 support discontinued](#webpack4-support-discontinued)
     - [Babel mode v7 exclusively](#babel-mode-v7-exclusively)
@@ -167,7 +169,7 @@
     - [Angular: Drop support for calling Storybook directly](#angular-drop-support-for-calling-storybook-directly)
     - [Angular: Application providers and ModuleWithProviders](#angular-application-providers-and-modulewithproviders)
     - [Angular: Removed legacy renderer](#angular-removed-legacy-renderer)
-    - [Angular: initializer functions](#angular-initializer-functions)
+    - [Angular: Initializer functions](#angular-initializer-functions)
     - [Next.js: use the `@storybook/nextjs` framework](#nextjs-use-the-storybooknextjs-framework)
     - [SvelteKit: needs the `@storybook/sveltekit` framework](#sveltekit-needs-the-storybooksveltekit-framework)
     - [Vue3: replaced app export with setup](#vue3-replaced-app-export-with-setup)
@@ -206,7 +208,7 @@
     - [Dropped addon-docs manual babel configuration](#dropped-addon-docs-manual-babel-configuration)
     - [Dropped addon-docs manual configuration](#dropped-addon-docs-manual-configuration)
     - [Autoplay in docs](#autoplay-in-docs)
-    - [Removed STORYBOOK_REACT_CLASSES global](#removed-storybook_react_classes-global)
+    - [Removed STORYBOOK\_REACT\_CLASSES global](#removed-storybook_react_classes-global)
   - [7.0 Deprecations and default changes](#70-deprecations-and-default-changes)
     - [storyStoreV7 enabled by default](#storystorev7-enabled-by-default)
     - [`Story` type deprecated](#story-type-deprecated)
@@ -419,6 +421,12 @@
   - [Packages renaming](#packages-renaming)
   - [Deprecated embedded addons](#deprecated-embedded-addons)
 
+## From version 8.4.x to 8.5.x
+
+### Indexing behavior of @storybook/experimental-addon-test is changed
+
+The Storybook test addon used to index stories based on the `test.include` field in the Vitest config file. This caused indexing issues with Storybook, because stories could have been indexed by Storybook and not Vitest, and vice versa. Starting in Storybook 8.5.0-alpha.18, we changed the indexing behavior so that it always uses the globs defined in the `stories` field in `.storybook/main.js` for a more consistent experience. It is now discouraged to use `test.include`, please remove it.
+
 ## From version 8.2.x to 8.3.x
 
 ### Removed `experimental_SIDEBAR_BOTTOM` and deprecated `experimental_SIDEBAR_TOP` addon types
diff --git a/code/addons/test/src/vitest-plugin/index.ts b/code/addons/test/src/vitest-plugin/index.ts
index 18749f75b9b9..fff8419a5a5f 100644
--- a/code/addons/test/src/vitest-plugin/index.ts
+++ b/code/addons/test/src/vitest-plugin/index.ts
@@ -13,8 +13,10 @@ import { MainFileMissingError } from 'storybook/internal/server-errors';
 import type { DocsOptions, StoriesEntry } from 'storybook/internal/types';
 
 import { join, resolve } from 'pathe';
+import picocolors from 'picocolors';
 import sirv from 'sirv';
 import { convertPathToPattern } from 'tinyglobby';
+import { dedent } from 'ts-dedent';
 
 import type { InternalOptions, UserOptions } from './types';
 
@@ -130,11 +132,21 @@ export const storybookTest = (options?: UserOptions): Plugin => {
 
       config.test ??= {};
 
-      config.test.include ??= [];
-      config.test.include.push(...storiesFiles.map((path) => convertPathToPattern(path)));
+      if (config.test.include?.length > 0) {
+        console.warn(
+          picocolors.yellow(dedent`
+            Warning: Starting in Storybook 8.5.0-alpha.18, the "test.include" option in Vitest is discouraged in favor of just using the "stories" field in your Storybook configuration.
 
-      config.test.exclude ??= [];
-      config.test.exclude.push('**/*.mdx');
+            The values you passed to "test.include" will be ignored, please remove them from your Vitest configuration where the Storybook plugin is applied.
+            
+            More info: https://github.com/storybookjs/storybook/blob/next/MIGRATION.md#indexing-behavior-of-storybookexperimental-addon-test-is-changed
+          `)
+        );
+      }
+
+      config.test.include = storiesFiles
+        .filter((path) => !path.endsWith('.mdx'))
+        .map((path) => convertPathToPattern(path));
 
       config.test.env ??= {};
       config.test.env = {