diff --git a/tsup.config.ts b/tsup.config.ts
index 7304091..d85148b 100644
--- a/tsup.config.ts
+++ b/tsup.config.ts
@@ -2,7 +2,7 @@ import { defineConfig } from 'tsup'
 
 export default defineConfig({
   clean: true,
-  format: ['esm'],
+  format: ['cjs'],
   entry: ['src/index.ts'],
   minify: true,
   splitting: true,