diff --git a/package.json b/package.json
index dd02a03..2cd2950 100644
--- a/package.json
+++ b/package.json
@@ -10,7 +10,8 @@
 		"start:dev": "nest start --watch",
 		"start:debug": "nest start --debug --watch",
 		"start:prod": "node dist/main",
-		"lint": "eslint \"{src,apps,libs,test}/**/*.ts\" --fix"
+		"lint": "eslint \"{src,apps,libs,test}/**/*.ts\" --fix",
+		"preinstall": "node -e \"if(process.env.npm_execpath.indexOf('yarn') === -1) throw new Error('You must use Yarn to install, not NPM')\""
 	},
 	"dependencies": {
 		"@apollo/server": "^4.11.2",