diff --git a/Plugin/OfflinePayments/Model/Purchaseorder/AddCustomerGroupCheckPlugin.php b/Plugin/OfflinePayments/Model/Purchaseorder/AddCustomerGroupCheckPlugin.php
index f74f3c3..18e4487 100644
--- a/Plugin/OfflinePayments/Model/Purchaseorder/AddCustomerGroupCheckPlugin.php
+++ b/Plugin/OfflinePayments/Model/Purchaseorder/AddCustomerGroupCheckPlugin.php
@@ -20,6 +20,9 @@ public function __construct(Config $config)
         $this->config = $config;
     }
 
+    /**
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
     public function afterIsAvailable(Purchaseorder $subject, bool $result, CartInterface $quote = null): bool
     {
         // if some other rule forbids this payment method, we forbid it as well