diff --git a/packages/vitest/src/index.ts b/packages/vitest/src/index.ts
index 71c19acb9d94..ef5c13dd9c49 100644
--- a/packages/vitest/src/index.ts
+++ b/packages/vitest/src/index.ts
@@ -1,3 +1,4 @@
+import type { UserConfig } from 'vite'
 import type { Plugin as PrettyFormatPlugin } from 'pretty-format'
 import type { Any, Anything } from './integrations/chai/jest-asymmetric-matchers'
 import type { MatcherState, MatchersObject } from './integrations/chai/types'
@@ -26,6 +27,10 @@ declare module 'vite' {
   }
 }
 
+export function defineConfig(config: UserConfig) {
+  return config
+}
+
 interface AsymmetricMatchersContaining {
   stringContaining(expected: string): any
   objectContaining(expected: any): any