diff --git a/src/Entities/DTO/MerchantBusinessEvent/CartInitiatedBusinessEvent.php b/src/Entities/DTO/MerchantBusinessEvent/CartInitiatedBusinessEvent.php
index e485693..91e4683 100644
--- a/src/Entities/DTO/MerchantBusinessEvent/CartInitiatedBusinessEvent.php
+++ b/src/Entities/DTO/MerchantBusinessEvent/CartInitiatedBusinessEvent.php
@@ -18,7 +18,7 @@ class CartInitiatedBusinessEvent extends AbstractBusinessEvent
     public function __construct($cartId)
     {
         $this->eventType = 'cart_initiated';
-        if(!is_string($cartId)){
+        if(empty($cartId) || !is_string($cartId)) {
             throw new ParametersException('CartId must be a string');
         }
         $this->cartId = $cartId;
diff --git a/src/Entities/DTO/MerchantBusinessEvent/OrderConfirmedBusinessEvent.php b/src/Entities/DTO/MerchantBusinessEvent/OrderConfirmedBusinessEvent.php
index b2f05b1..6c81229 100644
--- a/src/Entities/DTO/MerchantBusinessEvent/OrderConfirmedBusinessEvent.php
+++ b/src/Entities/DTO/MerchantBusinessEvent/OrderConfirmedBusinessEvent.php
@@ -43,6 +43,7 @@ class OrderConfirmedBusinessEvent extends AbstractBusinessEvent
      * @param bool $wasBNPLEligible
      * @param string $orderId
      * @param string $cartId
+     * @param string | null $almaPaymentId
      * @throws ParametersException
      */
     public function __construct($isAlmaP1X, $isAlmaBNPL, $wasBNPLEligible, $orderId, $cartId, $almaPaymentId = null)
diff --git a/tests/Unit/Entities/DTO/MerchantBusinessEvent/CartInitiatedBusinessEventTest.php b/tests/Unit/Entities/DTO/MerchantBusinessEvent/CartInitiatedBusinessEventTest.php
index bd20997..48b291d 100644
--- a/tests/Unit/Entities/DTO/MerchantBusinessEvent/CartInitiatedBusinessEventTest.php
+++ b/tests/Unit/Entities/DTO/MerchantBusinessEvent/CartInitiatedBusinessEventTest.php
@@ -29,6 +29,7 @@ public function testInvalidDataForBusinessEvent($cartId)
     public static function invalidDataForBusinessEventDataProvider()
     {
         return [
+            "cartId is an empty string" => [''],
             "cartId is an int" => [1],
             "cartId is a float" => [1.1],
             "cartId is an array" => [[]],