diff --git a/package.json b/package.json
index 19ae4a5..1154725 100644
--- a/package.json
+++ b/package.json
@@ -57,7 +57,7 @@
     "clean": "rimraf dist",
     "build": "npm run build:cjs && npm run build:esm && npm run copy:mjs",
     "build:cjs": "babel src --out-dir dist/cjs --config-file ./.babelrc --ignore '**/__tests__/**,**/__mocks__/**'",
-    "build:esm": "babel src --no-babelrc --out-dir dist/esm --config-file ./.babelrc.esm.json --ignore '**/__tests__/**,**/__mocks__/**'",
+    "build:esm": "babel src --no-babelrc --out-file-extension .mjs --out-dir dist/esm --config-file ./.babelrc.esm.json --ignore '**/__tests__/**,**/__mocks__/**'",
     "copy:mjs": "cp ./dist/esm/fire-event.js ./dist/esm/fire-event.mjs && cp ./dist/esm/pure.js ./dist/esm/pure.mjs && cp ./dist/esm/index.js ./dist/esm/index.mjs",
     "test": "jest src/__tests__ ",
     "test:watch": "npm test --watch",