diff --git a/package.json b/package.json
index 5a69169706..6e1be620f6 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,7 @@
     "cli-kintone": "cli.js"
   },
   "scripts": {
-    "preinstall": "npx cowsay 'Hello!'",
+    "preinstall": "npx github:pnpm/only-allow pnpm",
     "start": "run-s clean:lib 'build:tsc --watch'",
     "build": "run-s clean:lib build:tsc",
     "build:all": "run-s build build:artifacts",