diff --git a/package.json b/package.json
index 7332561..a6b1179 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,7 @@
   "dependencies": {
     "anonlytics-express": "0.2.0",
     "ascii-chart": "1.3.3",
-    "clean-css": "4.1.11",
+    "clean-css": "4.2.1",
     "compression": "1.7.2",
     "express": "4.14.1",
     "express-minify": "1.0.0",