diff --git a/packages/vite/src/node/plugins/esbuild.ts b/packages/vite/src/node/plugins/esbuild.ts
index bd1f7dfae90ba9..246fb8f9667a63 100644
--- a/packages/vite/src/node/plugins/esbuild.ts
+++ b/packages/vite/src/node/plugins/esbuild.ts
@@ -27,9 +27,9 @@ import { searchForWorkspaceRoot } from '..'
 const debug = createDebugger('vite:esbuild')
 
 const INJECT_HELPERS_IIFE_RE =
-  /^(.*?)((?:const|var) \S+=function\([^)]*\)\{"use strict";)/s
+  /^(.*?)((?:const|var)\s+\S+\s*=\s*function\s*\([^)]*\)\s*\{.*?"use strict";)/s
 const INJECT_HELPERS_UMD_RE =
-  /^(.*?)(\(function\([^)]*\)\{.+amd.+function\([^)]*\)\{"use strict";)/s
+  /^(.*?)(\(function\([^)]*\)\s*\{.+amd.+function\([^)]*\)\s*\{.*?"use strict";)/s
 
 let server: ViteDevServer
 
diff --git a/playground/lib/__tests__/lib.spec.ts b/playground/lib/__tests__/lib.spec.ts
index 50419ee5bb2874..5940f8ed0a93ce 100644
--- a/playground/lib/__tests__/lib.spec.ts
+++ b/playground/lib/__tests__/lib.spec.ts
@@ -16,15 +16,23 @@ describe.runIf(isBuild)('build', () => {
   test('umd', async () => {
     expect(await page.textContent('.umd')).toBe('It works')
     const code = readFile('dist/my-lib-custom-filename.umd.js')
+    const noMinifyCode = readFile('dist/nominify/my-lib-custom-filename.umd.js')
     // esbuild helpers are injected inside of the UMD wrapper
     expect(code).toMatch(/^\(function\(/)
+    expect(noMinifyCode).toMatch(/^\(function\(global/)
   })
 
   test('iife', async () => {
     expect(await page.textContent('.iife')).toBe('It works')
     const code = readFile('dist/my-lib-custom-filename.iife.js')
+    const noMinifyCode = readFile(
+      'dist/nominify/my-lib-custom-filename.iife.js',
+    )
     // esbuild helpers are injected inside of the IIFE wrapper
     expect(code).toMatch(/^var MyLib=function\(\)\{"use strict";/)
+    expect(noMinifyCode).toMatch(
+      /^var MyLib\s*=\s*function\(\)\s*\{.*?"use strict";/s,
+    )
   })
 
   test('Library mode does not include `preload`', async () => {
diff --git a/playground/lib/__tests__/serve.ts b/playground/lib/__tests__/serve.ts
index c12368fb581fea..0329eb34af56e4 100644
--- a/playground/lib/__tests__/serve.ts
+++ b/playground/lib/__tests__/serve.ts
@@ -61,6 +61,12 @@ export async function serve(): Promise<{ close(): Promise<void> }> {
       configFile: path.resolve(__dirname, '../vite.dyimport.config.js'),
     })
 
+    await build({
+      root: rootDir,
+      logLevel: 'warn', // output esbuild warns
+      configFile: path.resolve(__dirname, '../vite.nominify.config.js'),
+    })
+
     // start static file server
     const serve = sirv(path.resolve(rootDir, 'dist'))
     const httpServer = http.createServer((req, res) => {
diff --git a/playground/lib/vite.nominify.config.js b/playground/lib/vite.nominify.config.js
new file mode 100644
index 00000000000000..9c2eb7f1511611
--- /dev/null
+++ b/playground/lib/vite.nominify.config.js
@@ -0,0 +1,11 @@
+const baseConfig = require('./vite.config')
+
+module.exports = {
+  ...baseConfig,
+  build: {
+    ...baseConfig.build,
+    minify: false,
+    outDir: 'dist/nominify',
+  },
+  plugins: [],
+}