diff --git a/packages/angular/build/src/builders/dev-server/tests/behavior/build-assets_spec.ts b/packages/angular/build/src/builders/dev-server/tests/behavior/build-assets_spec.ts
index f7c7a0acb33a..7d3e1ffc414b 100644
--- a/packages/angular/build/src/builders/dev-server/tests/behavior/build-assets_spec.ts
+++ b/packages/angular/build/src/builders/dev-server/tests/behavior/build-assets_spec.ts
@@ -21,6 +21,26 @@ describeServeBuilder(executeDevServer, DEV_SERVER_BUILDER_INFO, (harness, setupT
     "import {foo} from 'unresolved'; /* a comment */const foo = `bar`;\n\n\n";
 
   describe('Behavior: "browser builder assets"', () => {
+    it('serves a project extensionless asset unmodified', async () => {
+      await harness.writeFile('src/extensionless', javascriptFileContent);
+
+      setupTarget(harness, {
+        assets: ['src/extensionless'],
+        optimization: {
+          scripts: true,
+        },
+      });
+
+      harness.useTarget('serve', {
+        ...BASE_OPTIONS,
+      });
+
+      const { result, response } = await executeOnceAndFetch(harness, 'extensionless');
+
+      expect(result?.success).toBeTrue();
+      expect(await response?.text()).toContain(javascriptFileContent);
+    });
+
     it('serves a project JavaScript asset unmodified', async () => {
       await harness.writeFile('src/extra.js', javascriptFileContent);
 
diff --git a/packages/angular/build/src/tools/vite/middlewares/assets-middleware.ts b/packages/angular/build/src/tools/vite/middlewares/assets-middleware.ts
index f0a137f578f8..e0074625afe0 100644
--- a/packages/angular/build/src/tools/vite/middlewares/assets-middleware.ts
+++ b/packages/angular/build/src/tools/vite/middlewares/assets-middleware.ts
@@ -45,8 +45,8 @@ export function createAngularAssetsMiddleware(
     // Rewrite all build assets to a vite raw fs URL
     const asset = assets.get(pathname);
     if (asset) {
-      // This is a workaround to serve CSS, JS and TS files without Vite transformations.
-      if (JS_TS_REGEXP.test(extension) || CSS_PREPROCESSOR_REGEXP.test(extension)) {
+      // This is a workaround to serve extensionless, CSS, JS and TS files without Vite transformations.
+      if (!extension || JS_TS_REGEXP.test(extension) || CSS_PREPROCESSOR_REGEXP.test(extension)) {
         const contents = readFileSync(asset.source);
         const etag = `W/${createHash('sha256').update(contents).digest('hex')}`;
         if (checkAndHandleEtag(req, res, etag)) {