diff --git a/core/package.json b/core/package.json
index b20516d..120eba4 100644
--- a/core/package.json
+++ b/core/package.json
@@ -9,19 +9,38 @@
     "lint:core-js": "node ./node_modules/eslint/bin/eslint.js --ext=.es6.js . --fix || exit 0"
   },
   "devDependencies": {
-    "babel-core": "6.24.0",
-    "babel-preset-es2015": "6.16.0",
+    "babel-plugin-external-helpers": "^6.22.0",
+    "babel-preset-env": "^1.3.3",
     "chokidar": "1.6.1",
-    "eslint": "3.18.0",
+    "eslint": "3.19.0",
     "eslint-config-airbnb": "14.1.0",
     "eslint-plugin-import": "2.2.0",
     "eslint-plugin-jsx-a11y": "4.0.0",
     "eslint-plugin-react": "6.10.3",
-    "glob": "7.1.1"
+    "glob": "7.1.1",
+    "rollup": "^0.41.6",
+    "rollup-plugin-babel": "^2.7.1",
+    "rollup-plugin-babili": "^2.0.0",
+    "rollup-plugin-commonjs": "^8.0.2",
+    "rollup-plugin-node-resolve": "^3.0.0"
   },
   "babel": {
     "presets": [
-      "es2015"
+      [
+        "env",
+        {
+          "modules": false,
+          "targets": {
+            "browsers": [
+              "last 2 versions",
+              "ie >= 11"
+            ]
+          }
+        }
+      ]
+    ],
+    "plugins": [
+      "external-helpers"
     ]
   }
 }
diff --git a/core/scripts/js/babel-es6-build.js b/core/scripts/js/babel-es6-build.js
index e073f6a..8e4ec74 100644
--- a/core/scripts/js/babel-es6-build.js
+++ b/core/scripts/js/babel-es6-build.js
@@ -11,44 +11,20 @@
 
 const fs = require('fs');
 const path = require('path');
-const babel = require('babel-core');
 const glob = require('glob');
 
-// Logging human-readable timestamp.
-const log = function (message) {
-  // eslint-disable-next-line no-console
-  console.log(`[${new Date().toTimeString().slice(0, 8)}] ${message}`);
-};
-
-function addSourceMappingUrl(code, loc) {
-  return code + '\n\n//# sourceMappingURL=' + path.basename(loc);
-}
-
-const changedOrAdded = (filePath) => {
-  babel.transformFile(filePath, {
-    sourceMaps: true,
-    comments: false
-  }, function (err, result) {
-    const fileName = filePath.slice(0, -7);
-    // we've requested for a sourcemap to be written to disk
-    let mapLoc = `${fileName}.js.map`;
-
-    fs.writeFile(mapLoc, JSON.stringify(result.map));
-    fs.writeFile(`${fileName}.js`, addSourceMappingUrl(result.code, mapLoc));
-
-    log(`'${filePath}' is being processed.`);
-  });
-};
+const changeOrAdded = require('./changeOrAdded');
+const log = require('./log');
 
 const fileMatch = './**/*.es6.js';
 const globOptions = {
-  ignore: 'node_modules/**'
+  ignore: './node_modules/**'
 };
 const processFiles = (error, filePaths) => {
   if (error) {
     process.exitCode = 1;
   }
-  filePaths.forEach(changedOrAdded);
+  filePaths.forEach(changeOrAdded);
 };
 glob(fileMatch, globOptions, processFiles);
 process.exitCode = 0;
diff --git a/core/scripts/js/babel-es6-watch.js b/core/scripts/js/babel-es6-watch.js
index d614774..00b0c2c 100644
--- a/core/scripts/js/babel-es6-watch.js
+++ b/core/scripts/js/babel-es6-watch.js
@@ -11,41 +11,17 @@
 
 const fs = require('fs');
 const path = require('path');
-const babel = require('babel-core');
 const chokidar = require('chokidar');
 
-// Logging human-readable timestamp.
-const log = function log(message) {
-  // eslint-disable-next-line no-console
-  console.log(`[${new Date().toTimeString().slice(0, 8)}] ${message}`);
-};
-
-function addSourceMappingUrl(code, loc) {
-  return `${code}\n\n//# sourceMappingURL=${path.basename(loc)}`;
-}
+const changeOrAdded = require('./changeOrAdded');
+const log = require('./log');
 
 const fileMatch = './**/*.es6.js';
 const watcher = chokidar.watch(fileMatch, {
   ignoreInitial: true,
-  ignored: 'node_modules/**'
+  ignored: './node_modules/**'
 });
 
-const changedOrAdded = (filePath) => {
-  babel.transformFile(filePath, {
-    sourceMaps: true,
-    comments: false
-  }, (err, result) => {
-    const fileName = filePath.slice(0, -7);
-    // we've requested for a sourcemap to be written to disk
-    const mapLoc = `${fileName}.js.map`;
-
-    fs.writeFileSync(mapLoc, JSON.stringify(result.map));
-    fs.writeFileSync(`${fileName}.js`, addSourceMappingUrl(result.code, mapLoc));
-
-    log(`'${filePath}' has been changed.`);
-  });
-};
-
 const unlinkHandler = (err) => {
   if (err) {
     log(err);
@@ -53,8 +29,8 @@ const unlinkHandler = (err) => {
 };
 
 watcher
-  .on('add', filePath => changedOrAdded(filePath))
-  .on('change', filePath => changedOrAdded(filePath))
+  .on('add', changeOrAdded)
+  .on('change', changeOrAdded)
   .on('unlink', (filePath) => {
     const fileName = filePath.slice(0, -7);
     fs.stat(`${fileName}.js`, () => {
diff --git a/core/scripts/js/changeOrAdded.js b/core/scripts/js/changeOrAdded.js
new file mode 100644
index 0000000..e0400b7
--- /dev/null
+++ b/core/scripts/js/changeOrAdded.js
@@ -0,0 +1,33 @@
+const rollup = require('rollup');
+const resolve = require('rollup-plugin-node-resolve');
+const commonjs = require('rollup-plugin-commonjs');
+const babel = require('rollup-plugin-babel');
+const babili = require('rollup-plugin-babili');
+
+const log = require('./log');
+
+module.exports = (filePath) => {
+  const moduleName = filePath.slice(0, -7);
+  log(`'${filePath}' is being processed.`);
+  rollup.rollup({
+    entry: filePath,
+    format: 'iife',
+    plugins: [
+      resolve({ jsnext: true, main: true }),
+      commonjs(),
+      babel({
+        exclude: 'node_modules/**'
+      }),
+      babili()
+    ]
+  })
+  .then(bundle => bundle.write({
+    format: 'iife',
+    moduleName: moduleName,
+    dest: `${moduleName}.js`,
+    sourceMap: true
+  }))
+  .then(() => {
+    log(`'${filePath}' is finished.`);
+  });
+}
diff --git a/core/scripts/js/log.js b/core/scripts/js/log.js
new file mode 100644
index 0000000..08349b3
--- /dev/null
+++ b/core/scripts/js/log.js
@@ -0,0 +1,4 @@
+module.exports = (message) => {
+  // Logging human-readable timestamp.
+  console.log(`[${new Date().toTimeString().slice(0, 8)}] ${message}`);
+}