diff --git a/package.json b/package.json
index 23b698d..8f37d05 100644
--- a/package.json
+++ b/package.json
@@ -20,7 +20,7 @@
     "node": ">=0.10"
   },
   "dependencies": {
-    "clean-css": "^4.2.1"
+    "clean-css": "^5.1.2"
   },
   "keywords": [
     "less plugins",