diff --git a/Makefile b/Makefile
deleted file mode 100644
index 8403cf6..0000000
--- a/Makefile
+++ /dev/null
@@ -1,3 +0,0 @@
-
-build:
-	@rollup --format=umd --output=css-doodle.js -- src/index.js
diff --git a/css-doodle.js b/css-doodle.js
index 571b958..d105b78 100644
--- a/css-doodle.js
+++ b/css-doodle.js
@@ -1,7 +1,7 @@
 (function (global, factory) {
-  typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
-  typeof define === 'function' && define.amd ? define(factory) :
-  (factory());
+	typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
+	typeof define === 'function' && define.amd ? define(factory) :
+	(factory());
 }(this, (function () { 'use strict';
 
 function nth(x, y, count) {
diff --git a/package.json b/package.json
index a92e8a8..ffaf730 100644
--- a/package.json
+++ b/package.json
@@ -12,7 +12,7 @@
     "url": "git+https://github.com/yuanchuan/css-doodle.git"
   },
   "devDependencies": {
-    "rollup": "^0.36.3"
+    "rollup": "^0.41.4"
   },
   "keywords": [
     "css",