diff --git a/CHANGELOG.md b/CHANGELOG.md
index a0f2876..2aabbf4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Increased default inflate chunk size to 64K.
 - Moved exported constants to `.constants`.
 - Switched to es6. Legacy es5 builds available in `/dist`.
+- Added esm build.
 - Structure of `/dist` folder changed.
 - Upgraded build tools to modern ones.
 
diff --git a/package.json b/package.json
index f4ebf80..8505d44 100644
--- a/package.json
+++ b/package.json
@@ -23,6 +23,10 @@
   ],
   "license": "(MIT AND Zlib)",
   "repository": "nodeca/pako",
+  "exports": {
+    "import": "./dist/pako.esm.js",
+    "require": "./index.js"
+  },
   "scripts": {
     "lint": "eslint .",
     "test": "npm run lint && mocha",
diff --git a/rollup.config.js b/rollup.config.js
index 9e34915..abc298f 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -75,6 +75,13 @@ export default [
       { file: 'dist/pako_inflate.es5.min.js', format: 'umd', name: 'pako', plugins: [ terser() ] }
     ],
     plugins: plugins_es5
+  },
+  // esm
+  {
+    input: 'index.js',
+    output: [
+      { file: 'dist/pako.esm.js', format: 'esm' }
+    ],
+    plugins: plugins
   }
-
 ];