diff --git a/package.json b/package.json
index 29623d4..0cd3748 100755
--- a/package.json
+++ b/package.json
@@ -26,7 +26,7 @@
   },
   "devDependencies": {
     "bannerjs": "~2.1.0",
-    "csso-cli": "3.0.0",
+    "csso-cli": "4.0.2",
     "less": "~4.1.2"
   },
   "license": "MIT"