diff --git a/package.json b/package.json
index b298304..9fa904d 100644
--- a/package.json
+++ b/package.json
@@ -23,7 +23,7 @@
   },
   "homepage": "https://github.com/programble/writ#readme",
   "devDependencies": {
-    "clean-css": "^3.3.6",
+    "clean-css": "^4.2.1",
     "marked": "^0.3.5",
     "nodemon": "^1.3.7"
   }