diff --git a/package.json b/package.json
index c2e26bb..d4b9e7b 100644
--- a/package.json
+++ b/package.json
@@ -36,7 +36,7 @@
   },
   "devDependencies": {
     "@types/encoding-japanese": "^1.0.15",
-    "@types/mocha": "^5.0.0",
+    "@types/mocha": "^7.0.2",
     "@types/node": "^9.3.0",
     "@types/power-assert": "^1.4.29",
     "cross-env": "^5.1.3",