diff --git a/app/PaymentDrivers/BraintreePaymentDriver.php b/app/PaymentDrivers/BraintreePaymentDriver.php
index 55c064581d40..aa9e6aac4fc6 100644
--- a/app/PaymentDrivers/BraintreePaymentDriver.php
+++ b/app/PaymentDrivers/BraintreePaymentDriver.php
@@ -40,7 +40,7 @@ class BraintreePaymentDriver extends BaseDriver
     /**
      * @var Gateway;
      */
-    public $gateway;
+    public Gateway $gateway;
 
     public static $methods = [
         GatewayType::CREDIT_CARD => CreditCard::class,