diff --git a/package.json b/package.json
index 481f7fe..0bbf9ac 100644
--- a/package.json
+++ b/package.json
@@ -11,8 +11,7 @@
   "exports": {
     ".": {
       "types": "./dist/index.d.ts",
-      "import": "./dist/index.js",
-      "require": "./dist/index.cjs"
+      "default": "./dist/index.js"
     }
   },
   "types": "./dist/index.d.ts",
diff --git a/rstack.config.ts b/rstack.config.ts
index 10e048d..e79f6ec 100644
--- a/rstack.config.ts
+++ b/rstack.config.ts
@@ -2,10 +2,9 @@
 import { define } from 'rstack';
 
 define.lib({
-  lib: [
-    { syntax: 'es2021', dts: true },
-    { format: 'cjs', syntax: 'es2021' },
-  ],
+  format: 'esm',
+  syntax: 'es2021',
+  dts: true,
   output: {
     target: 'node',
   },