diff --git a/tool/package.json b/tool/package.json
index fd95a9e5f5a..b58743f1f53 100644
--- a/tool/package.json
+++ b/tool/package.json
@@ -4,7 +4,7 @@
   "dependencies": {
     "browser-pack": "^5.0.1",
     "browserify": "^10.2.4",
-    "cson": "^3.0.1",
+    "cson": "^6.5.0",
     "css-parse": "1.0.3",
     "css-stringify": "1.0.3",
     "deps-sort": "^1.3.9",