diff --git a/ui/vite.config.ts b/ui/vite.config.ts
index 2e2d2b4..08fbbd2 100644
--- a/ui/vite.config.ts
+++ b/ui/vite.config.ts
@@ -6,7 +6,15 @@ import { paraglideVitePlugin } from '@inlang/paraglide-js';
 export default defineConfig({
   plugins: [
     // messages/{de,en}.json → src/paraglide (typed message functions); the language comes from src/i18n.ts
-    paraglideVitePlugin({ project: './project.inlang', outdir: './src/paraglide', outputStructure: 'message-modules', strategy: ['baseLocale'] }),
+    paraglideVitePlugin({
+      project: './project.inlang',
+      outdir: './src/paraglide',
+      // Paraglide 2's default: one module per locale in the dev server and tests (a few requests),
+      // one per message in production builds (tree shaking). v3 would serve virtual modules only Vite
+      // can resolve.
+      outputStructure: process.env.NODE_ENV === 'production' ? 'message-modules' : 'locale-modules',
+      strategy: ['baseLocale'],
+    }),
     react(),
   ],
   server: {