diff --git a/packages/vitest/package.json b/packages/vitest/package.json
index 2842d1dea114..a80a7bbb34d0 100644
--- a/packages/vitest/package.json
+++ b/packages/vitest/package.json
@@ -1,6 +1,5 @@
 {
   "name": "vitest",
-  "type": "module",
   "version": "0.13.1",
   "description": "A blazing fast unit test framework powered by Vite",
   "author": "Anthony Fu <anthonyfu117@hotmail.com>",
@@ -23,7 +22,7 @@
   "exports": {
     ".": {
       "types": "./dist/index.d.ts",
-      "import": "./dist/index.js"
+      "import": "./dist/index.mjs"
     },
     "./*": "./*",
     "./globals": {
@@ -34,12 +33,12 @@
     },
     "./node": {
       "types": "./dist/node.d.ts",
-      "import": "./dist/node.js"
+      "import": "./dist/node.mjs"
     },
     "./config": {
       "types": "./config.d.ts",
       "require": "./dist/config.cjs",
-      "import": "./dist/config.js"
+      "import": "./dist/config.mjs"
     }
   },
   "main": "./dist/index.js",
diff --git a/packages/vitest/rollup.config.js b/packages/vitest/rollup.config.js
index 8008ad0bf9ea..91d1d15a5c5f 100644
--- a/packages/vitest/rollup.config.js
+++ b/packages/vitest/rollup.config.js
@@ -61,6 +61,7 @@ export default ({ watch }) => [
     output: {
       dir: 'dist',
       format: 'esm',
+      entryFileNames: '[name].mjs',
       chunkFileNames: (chunkInfo) => {
         const id = chunkInfo.facadeModuleId || Object.keys(chunkInfo.modules).find(i => !i.includes('node_modules') && i.includes('src/'))
         if (id) {
@@ -70,9 +71,9 @@ export default ({ watch }) => [
               .filter(i => !['src', 'index', 'dist', 'node_modules'].some(j => i.includes(j)) && i.match(/^[\w_-]+$/))),
           )
           if (parts.length)
-            return `chunk-${parts.slice(-2).join('-')}.[hash].js`
+            return `chunk-${parts.slice(-2).join('-')}.[hash].mjs`
         }
-        return 'vendor-[name].[hash].js'
+        return 'vendor-[name].[hash].mjs'
       },
     },
     external,
@@ -94,7 +95,7 @@ export default ({ watch }) => [
         format: 'cjs',
       },
       {
-        file: 'dist/config.js',
+        file: 'dist/config.mjs',
         format: 'esm',
       },
     ],
diff --git a/packages/vitest/src/node/pool.ts b/packages/vitest/src/node/pool.ts
index fb73fc545226..3f170a6bb19d 100644
--- a/packages/vitest/src/node/pool.ts
+++ b/packages/vitest/src/node/pool.ts
@@ -18,7 +18,7 @@ export interface WorkerPool {
   close: () => Promise<void>
 }
 
-const workerPath = pathToFileURL(resolve(distDir, './worker.js')).href
+const workerPath = pathToFileURL(resolve(distDir, './worker.mjs')).href
 
 export function createPool(ctx: Vitest): WorkerPool {
   const threadsCount = ctx.config.watch
diff --git a/packages/vitest/src/runtime/mocker.ts b/packages/vitest/src/runtime/mocker.ts
index b63783aa7453..17a10ea051ef 100644
--- a/packages/vitest/src/runtime/mocker.ts
+++ b/packages/vitest/src/runtime/mocker.ts
@@ -230,7 +230,7 @@ export class VitestMocker {
   private async ensureSpy() {
     if (VitestMocker.spyModule)
       return
-    VitestMocker.spyModule = await this.request(`/@fs/${slash(resolve(distDir, 'spy.js'))}`) as typeof import('../integrations/spy')
+    VitestMocker.spyModule = await this.request(`/@fs/${slash(resolve(distDir, 'spy.mjs'))}`) as typeof import('../integrations/spy')
   }
 
   public async requestWithMock(dep: string) {
diff --git a/packages/vitest/src/runtime/worker.ts b/packages/vitest/src/runtime/worker.ts
index fbb9701e9eff..9159535cecf6 100644
--- a/packages/vitest/src/runtime/worker.ts
+++ b/packages/vitest/src/runtime/worker.ts
@@ -38,7 +38,7 @@ async function startViteNode(ctx: WorkerContext) {
 
   const { run } = (await executeInViteNode({
     files: [
-      resolve(distDir, 'entry.js'),
+      resolve(distDir, 'entry.mjs'),
     ],
     fetchModule(id) {
       return rpc().fetch(id)
diff --git a/packages/vitest/vitest.mjs b/packages/vitest/vitest.mjs
index 02dd4714b903..dfaf05f626b7 100755
--- a/packages/vitest/vitest.mjs
+++ b/packages/vitest/vitest.mjs
@@ -1,2 +1,2 @@
 #!/usr/bin/env node
-import './dist/cli.js'
+import './dist/cli.mjs'