diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
index eeb76c4e..caff5677 100644
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -22,14 +22,14 @@ There are two situations in which we create manual PRs to update translations:
 
 ### Adding a language
 
-* [ ] Edit `src/supported-locales.js`:
+* [ ] Edit `src/supported-locales.mjs`:
   * [ ] Add entry for the language in the `locales` const
   * [ ] Check if language is right-to-left. If so:
     * Add entry in `rtlLocales`
 
 * [ ] Check if the new language uses a country code
   * Check [https://www.transifex.com/explore/languages](https://www.transifex.com/explore/languages). If the language has a country code:
-  * [ ] Edit `src/supported-locales.js`:
+  * [ ] Edit `src/supported-locales.mjs`:
     * Add new entry to `localeMap`. Format is `'<W3C HTML browser locale string>': '<Transifex ICU locale string>'`
   * [ ] Edit `.tx/config`:
     * Add to the `lang_map` list. Format is `<Transifex ICU locale string>:<W3C HTML browser locale string>`
@@ -42,14 +42,14 @@ There are two situations in which we create manual PRs to update translations:
 * [ ] Check if locale is in `react-intl`
   * Look in [https://unpkg.com/react-intl/locale-data/](https://unpkg.com/react-intl/locale-data/)
   * If not in `react-intl`:
-    * [ ] Edit `src/supported-locales.js`:
+    * [ ] Edit `src/supported-locales.mjs`:
       * In `customLocales`, add entry with parent set to a `react-intl` locale
     * [ ] Edit `src/index.js`:
       * In `localeData`, add entry for parent locale
 
 * [ ] Update translations per the "Updating translations" section above
 * [ ] Confirm that we see changes to:
-    * [ ] `src/supported-locales.js`
+    * [ ] `src/supported-locales.mjs`
     * [ ] `src/index.js`
     * [ ] `.tx/config` (if language needed a new locale)
     * [ ] Multiple files like `editor/<resource>/<lang code>.json`
diff --git a/lib/transifex.js b/lib/transifex.js
index ab5a76bf..c0244e7e 100644
--- a/lib/transifex.js
+++ b/lib/transifex.js
@@ -1,4 +1,4 @@
-#!/usr/bin/env babel-node
+#!/usr/bin/env node
 
 /**
  * @fileoverview
diff --git a/lib/validate.js b/lib/validate.mjs
similarity index 100%
rename from lib/validate.js
rename to lib/validate.mjs
diff --git a/package.json b/package.json
index fd6d3718..906002f5 100644
--- a/package.json
+++ b/package.json
@@ -10,31 +10,31 @@
   },
   "scripts": {
     "build": "npm run clean && npm run build:data && webpack --progress --colors --bail",
-    "build:data": "babel-node scripts/build-data",
+    "build:data": "node scripts/build-data.mjs",
     "clean": "rimraf ./dist ./locales && mkdirp dist locales",
     "lint": "npm run lint:js && npm run lint:json",
-    "lint:js": "eslint . --ext .js",
+    "lint:js": "eslint . --ext .js,.mjs,.cjs",
     "lint:json": "jshint -e .json www editor/blocks editor/extensions editor/interface editor/paint-editor",
     "prepare": "husky install",
-    "pull:blocks": "babel-node scripts/tx-pull-editor scratch-editor blocks ./editor/blocks/",
+    "pull:blocks": "node scripts/tx-pull-editor.mjs scratch-editor blocks ./editor/blocks/",
     "pull:editor": "npm run pull:blocks && npm run pull:extensions && npm run pull:paint && npm run pull:interface",
-    "pull:extensions": "babel-node scripts/tx-pull-editor scratch-editor extensions ./editor/extensions/",
+    "pull:extensions": "node scripts/tx-pull-editor.mjs scratch-editor extensions ./editor/extensions/",
     "pull:help": "npm run pull:help:names && npm run pull:help:articles",
     "pull:help:articles": "./scripts/tx-pull-help-articles.js",
     "pull:help:names": "./scripts/tx-pull-help-names.js",
-    "pull:interface": "babel-node scripts/tx-pull-editor scratch-editor interface ./editor/interface/",
-    "pull:paint": "babel-node scripts/tx-pull-editor scratch-editor paint-editor ./editor/paint-editor/",
-    "pull:www": "babel-node scripts/tx-pull-www ./www",
-    "push:help": "./scripts/tx-push-help.js",
+    "pull:interface": "node scripts/tx-pull-editor.mjs scratch-editor interface ./editor/interface/",
+    "pull:paint": "node scripts/tx-pull-editor.mjs scratch-editor paint-editor ./editor/paint-editor/",
+    "pull:www": "node scripts/tx-pull-www.mjs ./www",
+    "push:help": "./scripts/tx-push-help.mjs",
     "sync:help": "npm run push:help && npm run pull:help",
     "test": "npm run lint:js && npm run validate:editor && npm run validate:www && npm run build && npm run lint:json",
     "update": "scripts/update-translations.sh",
-    "validate:blocks": "babel-node scripts/validate-translations ./editor/blocks/",
+    "validate:blocks": "node scripts/validate-translations.mjs ./editor/blocks/",
     "validate:editor": "npm run validate:blocks && npm run validate:extensions && npm run validate:interface && npm run validate:paint",
-    "validate:extensions": "babel-node scripts/validate-translations ./editor/extensions/ && babel-node scripts/validate-extension-inputs",
-    "validate:interface": "babel-node scripts/validate-translations ./editor/interface/",
-    "validate:paint": "babel-node scripts/validate-translations ./editor/paint-editor/",
-    "validate:www": "babel-node scripts/validate-www ./www"
+    "validate:extensions": "node scripts/validate-translations.mjs ./editor/extensions/ && node scripts/validate-extension-inputs.mjs",
+    "validate:interface": "node scripts/validate-translations.mjs ./editor/interface/",
+    "validate:paint": "node scripts/validate-translations.mjs ./editor/paint-editor/",
+    "validate:www": "node scripts/validate-www.mjs ./www"
   },
   "repository": {
     "type": "git",
diff --git a/scripts/build-data.js b/scripts/build-data.mjs
similarity index 98%
rename from scripts/build-data.js
rename to scripts/build-data.mjs
index 8709706d..b6f12aaa 100755
--- a/scripts/build-data.js
+++ b/scripts/build-data.mjs
@@ -42,7 +42,7 @@ import * as fs from 'fs';
 import * as path from 'path';
 import {sync as mkdirpSync} from 'mkdirp';
 import defaultsDeep from 'lodash.defaultsdeep';
-import locales from '../src/supported-locales.js';
+import locales from '../src/supported-locales.mjs';
 
 const MSGS_DIR = './locales/';
 mkdirpSync(MSGS_DIR);
diff --git a/scripts/tx-pull-editor.js b/scripts/tx-pull-editor.mjs
similarity index 94%
rename from scripts/tx-pull-editor.js
rename to scripts/tx-pull-editor.mjs
index 3cb0c528..c1eff567 100644
--- a/scripts/tx-pull-editor.js
+++ b/scripts/tx-pull-editor.mjs
@@ -1,4 +1,4 @@
-#!/usr/bin/env babel-node
+#!/usr/bin/env node
 
 /**
  * @fileoverview
@@ -29,8 +29,8 @@ if (!process.env.TX_TOKEN || args.length < 3) {
 import fs from 'fs';
 import path from 'path';
 import {txPull} from '../lib/transifex.js';
-import {validateTranslations} from '../lib/validate.js';
-import locales, {localeMap} from '../src/supported-locales.js';
+import {validateTranslations} from '../lib/validate.mjs';
+import locales, {localeMap} from '../src/supported-locales.mjs';
 import {batchMap} from '../lib/batch.js';
 
 // Globals
diff --git a/scripts/tx-pull-www.js b/scripts/tx-pull-www.mjs
similarity index 97%
rename from scripts/tx-pull-www.js
rename to scripts/tx-pull-www.mjs
index 585ce09f..dbff18d9 100755
--- a/scripts/tx-pull-www.js
+++ b/scripts/tx-pull-www.mjs
@@ -1,4 +1,4 @@
-#!/usr/bin/env babel-node
+#!/usr/bin/env node
 
 /**
  * @fileoverview
@@ -31,7 +31,7 @@ import fs from 'fs';
 import path from 'path';
 import mkdirp from 'mkdirp';
 import {txPull, txResources} from '../lib/transifex.js';
-import locales, {localeMap} from '../src/supported-locales.js';
+import locales, {localeMap} from '../src/supported-locales.mjs';
 import {batchMap} from '../lib/batch.js';
 
 // Globals
diff --git a/scripts/tx-push-help.js b/scripts/tx-push-help.mjs
similarity index 99%
rename from scripts/tx-push-help.js
rename to scripts/tx-push-help.mjs
index 7109b699..bfbb9099 100755
--- a/scripts/tx-push-help.js
+++ b/scripts/tx-push-help.mjs
@@ -1,4 +1,4 @@
-#!/usr/bin/env babel-node
+#!/usr/bin/env node
 
 /**
  * @fileoverview
diff --git a/scripts/validate-extension-inputs.js b/scripts/validate-extension-inputs.mjs
similarity index 97%
rename from scripts/validate-extension-inputs.js
rename to scripts/validate-extension-inputs.mjs
index 9a374e87..5d6ce61d 100644
--- a/scripts/validate-extension-inputs.js
+++ b/scripts/validate-extension-inputs.mjs
@@ -1,4 +1,4 @@
-#!/usr/bin/env babel-node
+#!/usr/bin/env node
 
 /**
  * @fileoverview
@@ -9,7 +9,7 @@ import fs from 'fs';
 import path from 'path';
 import async from 'async';
 import assert from 'assert';
-import locales from '../src/supported-locales.js';
+import locales from '../src/supported-locales.mjs';
 
 // Globals
 const JSON_DIR = path.join(process.cwd(), '/editor/extensions');
diff --git a/scripts/validate-translations.js b/scripts/validate-translations.mjs
similarity index 86%
rename from scripts/validate-translations.js
rename to scripts/validate-translations.mjs
index d2e24fd8..ee4654ce 100644
--- a/scripts/validate-translations.js
+++ b/scripts/validate-translations.mjs
@@ -1,4 +1,4 @@
-#!/usr/bin/env babel-node
+#!/usr/bin/env node
 
 /**
  * @fileoverview
@@ -8,7 +8,7 @@
 const args = process.argv.slice(2);
 const usage = `
  Validate translation json. Usage:
-   babel-node validate_translations.js path
+   node validate_translations.mjs path
      path: where to find the downloaded json files
  `;
 // Fail immediately if the TX_TOKEN is not defined
@@ -19,8 +19,8 @@ if (args.length < 1) {
 import fs from 'fs';
 import path from 'path';
 import async from 'async';
-import {validateTranslations} from '../lib/validate.js';
-import locales from '../src/supported-locales.js';
+import {validateTranslations} from '../lib/validate.mjs';
+import locales from '../src/supported-locales.mjs';
 
 // Globals
 const JSON_DIR = path.resolve(args[0]);
diff --git a/scripts/validate-www.js b/scripts/validate-www.mjs
similarity index 90%
rename from scripts/validate-www.js
rename to scripts/validate-www.mjs
index 0a5bbff0..e8454083 100755
--- a/scripts/validate-www.js
+++ b/scripts/validate-www.mjs
@@ -1,4 +1,4 @@
-#!/usr/bin/env babel-node
+#!/usr/bin/env node
 
 /**
  * @fileoverview
@@ -8,7 +8,7 @@
 const args = process.argv.slice(2);
 const usage = `
  Validate translation json. Usage:
-   babel-node validate_www.js path
+   node validate_www.mjs path
      path: root folder for all the www resource folders
  `;
 if (args.length < 1) {
@@ -19,8 +19,8 @@ import fs from 'fs';
 import path from 'path';
 import glob from 'glob';
 import async from 'async';
-import {validateTranslations} from '../lib/validate.js';
-import locales from '../src/supported-locales.js';
+import {validateTranslations} from '../lib/validate.mjs';
+import locales from '../src/supported-locales.mjs';
 
 // Globals
 const WWW_DIR = path.resolve(args[0]);
diff --git a/src/index.js b/src/index.js
deleted file mode 100644
index 43007c05..00000000
--- a/src/index.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import localeData from './locale-data.js';
-import locales, {localeMap, isRtl} from './supported-locales.js';
-export {locales as default, localeData, localeMap, isRtl};
diff --git a/src/index.mjs b/src/index.mjs
new file mode 100644
index 00000000..444dd78b
--- /dev/null
+++ b/src/index.mjs
@@ -0,0 +1,3 @@
+import localeData from './locale-data.mjs';
+import locales, {localeMap, isRtl} from './supported-locales.mjs';
+export {locales as default, localeData, localeMap, isRtl};
diff --git a/src/locale-data.js b/src/locale-data.mjs
similarity index 98%
rename from src/locale-data.js
rename to src/locale-data.mjs
index 49b366fc..949f863f 100644
--- a/src/locale-data.js
+++ b/src/locale-data.mjs
@@ -72,7 +72,7 @@ import xh from './locale-data/xh';
 import zh from './locale-data/zh';
 import zu from './locale-data/zu';
 
-import {customLocales} from './supported-locales.js';
+import {customLocales} from './supported-locales.mjs';
 
 let localeData = [].concat(
     en,
diff --git a/src/supported-locales.js b/src/supported-locales.mjs
similarity index 100%
rename from src/supported-locales.js
rename to src/supported-locales.mjs
diff --git a/webpack.config.js b/webpack.config.js
index 878b83d7..25735e40 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -22,8 +22,8 @@ module.exports = {
     },
     entry: {
         l10n: './src/index.js',
-        supportedLocales: './src/supported-locales.js',
-        localeData: './src/locale-data.js'
+        supportedLocales: './src/supported-locales.mjs',
+        localeData: './src/locale-data.mjs'
     },
     output: {
         path: path.resolve(__dirname, 'dist'),