diff --git a/package.json b/package.json
index dc5a557bfa..2327b905b1 100644
--- a/package.json
+++ b/package.json
@@ -41,7 +41,7 @@
     "buble": "^0.19.3",
     "buble-loader": "^0.5.1",
     "chaikin-smooth": "^1.0.4",
-    "clean-css-cli": "4.1.11",
+    "clean-css-cli": "4.2.0",
     "copy-webpack-plugin": "^4.4.1",
     "coveralls": "3.0.1",
     "eslint": "5.0.1",