diff --git a/README.md b/README.md
index 61b9b11..07bd7a3 100644
--- a/README.md
+++ b/README.md
@@ -37,6 +37,15 @@ const Polygons = Kage.Polygons;
 const Buhin = Kage.Buhin;
 ```
 
+Bundled ESM file is also available:
+```html
+<script type="module">
+  import { Kage, Polygons } from "https://unpkg.com/@kurgm/kage-engine@0.6.0/dist/kage.min.mjs";
+
+  // Your code goes here
+</script>
+```
+
 ### Drawing glyphs
 
 *See [docs](docs/classes/Kage.md) for more detailed API documentations (of development version).*
diff --git a/rollup.config.mjs b/rollup.config.mjs
index d9a8142..a352714 100644
--- a/rollup.config.mjs
+++ b/rollup.config.mjs
@@ -9,28 +9,46 @@ const banner = `/*! kage.js v${pkg.version}
  */`;
 
 /** @type {import("rollup").RollupOptions} */
-const options = {
-	input: "src/browser.ts",
-	output: [
-		{
-			file: "dist/kage.js",
-			format: "iife",
-			name: "Kage",
-			exports: "default",
-			banner,
-		},
-		{
-			file: "dist/kage.min.js",
-			format: "iife",
-			name: "Kage",
-			exports: "default",
-			banner,
-			plugins: [terser()],
-		},
-	],
-	plugins: [
-		typescript({}),
-	],
-};
+const options = [
+	{
+		input: "src/browser.ts",
+		output: [
+			{
+				file: "dist/kage.js",
+				format: "iife",
+				name: "Kage",
+				exports: "default",
+				banner,
+			},
+			{
+				file: "dist/kage.min.js",
+				format: "iife",
+				name: "Kage",
+				exports: "default",
+				banner,
+				plugins: [terser()],
+			},
+		],
+		plugins: [
+			typescript({}),
+		],
+	},
+	{
+		input: "src/index.ts",
+		output: [
+			{
+				file: "dist/kage.min.mjs",
+				format: "es",
+				banner,
+				plugins: [terser()],
+			},
+		],
+		plugins: [
+			typescript({
+				target: "es6",
+			}),
+		],
+	},
+];
 
 export default options;