diff --git a/package.json b/package.json
index 95701656b..4616ecd99 100644
--- a/package.json
+++ b/package.json
@@ -47,7 +47,7 @@
     "url": "https://github.com/FineUploader/fine-uploader/issues"
   },
   "devDependencies": {
-    "clean-css-cli": "4.0.8",
+    "clean-css-cli": "5.3.0",
     "jscs": "3.0.7",
     "jshint": "2.9.4",
     "karma": "1.5.0",