diff --git a/packages/ts/package.json b/packages/ts/package.json
index 594dc63..b9dd979 100644
--- a/packages/ts/package.json
+++ b/packages/ts/package.json
@@ -9,7 +9,7 @@
   "author": "one-chan",
   "license": "MIT",
   "devDependencies": {
-    "@types/mocha": "^5.0.0",
+    "@types/mocha": "^9.0.0",
     "mocha": "^5.1.0",
     "jest": "^22.4.3",
     "typescript": "^2.7.1"
diff --git a/yarn.lock b/yarn.lock
index 9d086bf..208806d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -10,9 +10,9 @@
     esutils "^2.0.2"
     js-tokens "^3.0.0"
 
-"@types/mocha@^5.0.0":
-  version "5.0.0"
-  resolved "https://registry.yarnpkg.com/@types/mocha/-/mocha-5.0.0.tgz#a3014921991066193f6c8e47290d4d598dfd19e6"
+"@types/mocha@^9.0.0":
+  version "9.0.0"
+  resolved "https://registry.yarnpkg.com/@types/mocha/-/mocha-9.0.0.tgz#3205bcd15ada9bc681ac20bef64e9e6df88fd297"
 
 "@types/node@*", "@types/node@^9.6.5":
   version "9.6.5"