diff --git a/.gitignore b/.gitignore
index 5dc72081..c90d1cc7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,7 +16,7 @@ coverage
 /locale
 /plugin
 dayjs.min.js
-/lib
+/esm
 
 #dev
 demo.js
diff --git a/.npmignore b/.npmignore
index 3e276781..4f08223c 100644
--- a/.npmignore
+++ b/.npmignore
@@ -13,6 +13,7 @@ package-lock.json
 coverage
 
 # dev
+src
 test
 build
 .babelrc
diff --git a/package.json b/package.json
index bfd8556a..22ceb719 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,7 @@
     "test": "TZ=Pacific/Auckland npm run test-tz && TZ=Europe/London npm run test-tz && npm run test-tz && jest",
     "test-tz": "jest test/timezone.test --coverage=false",
     "lint": "./node_modules/.bin/eslint src/* test/* build/*",
-    "babel": "BABEL_ENV=build babel src --out-dir lib --copy-files",
+    "babel": "cross-env BABEL_ENV=build babel src --out-dir esm --copy-files",
     "build": "cross-env BABEL_ENV=build node build && npm run size",
     "sauce": "npx karma start karma.sauce.conf.js",
     "test:sauce": "npm run sauce -- 0 && npm run sauce -- 1 && npm run sauce -- 2  && npm run sauce -- 3",