diff --git a/package.json b/package.json
index 8d68f89..ba9f9df 100644
--- a/package.json
+++ b/package.json
@@ -18,7 +18,7 @@
   },
   "homepage": "https://github.com/unlessquit/s2#readme",
   "devDependencies": {
-    "mocha": "^3.2.0",
+    "mocha": "^9.0.1",
     "nodemon": "^1.11.0",
     "standard": "^9.0.2",
     "supertest": "^3.0.0"