diff --git a/src/Payment/Application/DTO/CreateTransactionRequest.php b/src/Payment/Application/DTO/CreateTransactionRequest.php
index 87bdac2..601ca96 100644
--- a/src/Payment/Application/DTO/CreateTransactionRequest.php
+++ b/src/Payment/Application/DTO/CreateTransactionRequest.php
@@ -16,7 +16,7 @@
 final readonly class CreateTransactionRequest
 {
     /**
-     * @param array<CartItem> $cart
+     * @param array<CartItem>|null $cart
      */
     public function __construct(
         public string $amount,
diff --git a/src/Payment/Domain/ValueObject/Address.php b/src/Payment/Domain/ValueObject/Address.php
index e9aaaa7..339ece4 100644
--- a/src/Payment/Domain/ValueObject/Address.php
+++ b/src/Payment/Domain/ValueObject/Address.php
@@ -12,7 +12,7 @@ public function __construct(
         public ?string $firstName = null,
         public ?string $lastName = null,
         public ?string $street = null,
-        public ?string $building = null,
+        public ?string $buildingNumber = null,
         public ?string $flat = null,
         public ?string $city = null,
         public ?string $region = null,
@@ -37,7 +37,7 @@ public function toArray(): array
             'firstName' => $this->firstName,
             'lastName' => $this->lastName,
             'street' => $this->street,
-            'building' => $this->building,
+            'buildingNumber' => $this->buildingNumber,
             'flat' => $this->flat,
             'city' => $this->city,
             'region' => $this->region,
diff --git a/tests/Unit/Domain/ValueObject/AddressTest.php b/tests/Unit/Domain/ValueObject/AddressTest.php
index 77bd4c6..6d0b693 100644
--- a/tests/Unit/Domain/ValueObject/AddressTest.php
+++ b/tests/Unit/Domain/ValueObject/AddressTest.php
@@ -18,7 +18,7 @@ public function createsWithAllFields(): void
             firstName: 'Jan',
             lastName: 'Kowalski',
             street: 'Główna',
-            building: '10',
+            buildingNumber: '10',
             flat: '5A',
             city: 'Warszawa',
             region: 'Mazowieckie',
@@ -33,7 +33,7 @@ public function createsWithAllFields(): void
         $this->assertSame('Jan', $address->firstName);
         $this->assertSame('Kowalski', $address->lastName);
         $this->assertSame('Główna', $address->street);
-        $this->assertSame('10', $address->building);
+        $this->assertSame('10', $address->buildingNumber);
         $this->assertSame('5A', $address->flat);
         $this->assertSame('Warszawa', $address->city);
         $this->assertSame('Mazowieckie', $address->region);
@@ -53,7 +53,7 @@ public function createsWithNoFields(): void
         $this->assertNull($address->firstName);
         $this->assertNull($address->lastName);
         $this->assertNull($address->street);
-        $this->assertNull($address->building);
+        $this->assertNull($address->buildingNumber);
         $this->assertNull($address->flat);
         $this->assertNull($address->city);
         $this->assertNull($address->region);
@@ -72,7 +72,7 @@ public function convertsToArrayWithAllFields(): void
             firstName: 'Anna',
             lastName: 'Nowak',
             street: 'Kwiatowa',
-            building: '5',
+            buildingNumber: '5',
             city: 'Kraków',
             postalCode: '30-001',
             country: 'PL',
@@ -83,7 +83,7 @@ public function convertsToArrayWithAllFields(): void
         $this->assertSame('Anna', $array['firstName']);
         $this->assertSame('Nowak', $array['lastName']);
         $this->assertSame('Kwiatowa', $array['street']);
-        $this->assertSame('5', $array['building']);
+        $this->assertSame('5', $array['buildingNumber']);
         $this->assertSame('Kraków', $array['city']);
         $this->assertSame('30-001', $array['postalCode']);
         $this->assertSame('PL', $array['country']);