diff --git a/tests/UnitTests/Builders/BasketBuilder.cs b/tests/UnitTests/Builders/BasketBuilder.cs
index 08dd04a..8378759 100644
--- a/tests/UnitTests/Builders/BasketBuilder.cs
+++ b/tests/UnitTests/Builders/BasketBuilder.cs
@@ -6,7 +6,7 @@
 public class BasketBuilder
 {
     private Basket _basket;
-    public string BasketBuyerId => "testbuyerId@test.com";
+    public Username BasketBuyerId => new("testbuyerId@test.com");
 
     public int BasketId => 1;