diff --git a/vite.config.ts b/vite.config.ts
index 8b0b56d3e..d30322648 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -66,7 +66,7 @@ export default defineConfig({
     lib: isLibraryMode
       ? {
           entry: path.resolve(__dirname, './app/javascript/entrypoints/sdk.js'),
-          formats: ['umd'], // UMD format for single file
+          formats: ['cjs'], // CJS format for single file
           name: 'sdk',
         }
       : undefined,