diff --git a/package.json b/package.json
index 41b493c..6fc9c0c 100644
--- a/package.json
+++ b/package.json
@@ -25,6 +25,7 @@
 	],
 	"dependencies": {},
 	"scripts": {
+		"dev": "(npm run tsc-watch -- --preserveWatchOutput & p1=$!; npm run rollup-build -- --watch & p2=$!; wait $p1 $p2)",
 		"build": "rimraf dist .tmp && node scripts/write-version.js && npm run tsc && npm run rollup-build",
 		"rollup-build": "rollup -c ./rollup.config.js",
 		"tsc": "tsc",
diff --git a/rollup.config.js b/rollup.config.js
index 8641d95..f25911b 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -5,28 +5,34 @@ export default [
 		input: '.tmp/Index.js',
 		// https://github.com/rollup/rollup/wiki/Troubleshooting#this-is-undefined
 		context: 'this',
+		watch: {clearScreen: false},
 		output: [
 			{
 				file: 'dist/tween.umd.js',
 				name: 'TWEEN',
 				format: 'umd',
+				exports: 'named',
 			},
 			{
 				file: 'dist/tween.amd.js',
 				format: 'amd',
+				exports: 'named',
 			},
 			{
 				file: 'dist/tween.cjs.js',
 				format: 'cjs',
+				exports: 'named',
 			},
 			{
 				file: 'dist/tween.esm.js',
 				format: 'es',
+				exports: 'named',
 			},
 		],
 	},
 	{
 		input: './.tmp/Index.d.ts',
+		watch: {clearScreen: false},
 		output: [{file: 'dist/tween.d.ts', format: 'es'}],
 		plugins: [dts()],
 	},