diff --git a/package.json b/package.json
index b509263..7a71a95 100644
--- a/package.json
+++ b/package.json
@@ -7,7 +7,7 @@
   "bugs": "https://github.com/mobify/mobify-client/issues",
   "dependencies": {
     "async": "0.1.22",
-    "clean-css": "1.0.12",
+    "clean-css": "4.2.1",
     "coffee-script": "1.3.3",
     "commander": "1.0.4",
     "connect": "^2.30.2",