diff --git a/201-vmss-custom-script-windows/azuredeploy.parameters.json b/201-vmss-custom-script-windows/azuredeploy.parameters.json
index f98aacc3..47127df3 100644
--- a/201-vmss-custom-script-windows/azuredeploy.parameters.json
+++ b/201-vmss-custom-script-windows/azuredeploy.parameters.json
@@ -9,7 +9,7 @@
 	    "value": "[concat('Subscription#', substring(resourcegroup().id, 15, 36))]"
 	},
 	"vmssName": {
-	    "value": "[substring(concat('winvmss', resourceGroup().Name), 0, 10)]"
+	    "value": "[substring(concat('winvmss', resourceGroup().Name), 0, 9)]"
 	}
     }
 }