diff --git a/package.json b/package.json
index e3a3da8..0c6f5c0 100644
--- a/package.json
+++ b/package.json
@@ -79,7 +79,7 @@
     "html-webpack-tags-plugin": "^2.0.15",
     "husky": "^2.3.0",
     "lint-staged": "^8.1.7",
-    "mocha": "^5.2.0",
+    "mocha": "^9.0.3",
     "npm-run-all": "^4.1.5",
     "polymer-cli": "^1.9.10",
     "prettier": "^1.17.1",