diff --git a/app/code/Magento/Quote/Api/Data/CartInterface.php b/app/code/Magento/Quote/Api/Data/CartInterface.php
index 551833e3effb1..b87869de6b3df 100644
--- a/app/code/Magento/Quote/Api/Data/CartInterface.php
+++ b/app/code/Magento/Quote/Api/Data/CartInterface.php
@@ -223,14 +223,14 @@ public function setBillingAddress(\Magento\Quote\Api\Data\AddressInterface $bill
     /**
      * Returns the reserved order ID for the cart.
      *
-     * @return int|null Reserved order ID. Otherwise, null.
+     * @return string|null Reserved order ID. Otherwise, null.
      */
     public function getReservedOrderId();
 
     /**
      * Sets the reserved order ID for the cart.
      *
-     * @param int $reservedOrderId
+     * @param string $reservedOrderId
      * @return $this
      */
     public function setReservedOrderId($reservedOrderId);