diff --git a/SVSim.EmulatedEntrypoint/Models/Dtos/Requests/ImmutableData/CardMasterRequest.cs b/SVSim.EmulatedEntrypoint/Models/Dtos/Requests/ImmutableData/CardMasterRequest.cs
index e9584d26..7e69b906 100644
--- a/SVSim.EmulatedEntrypoint/Models/Dtos/Requests/ImmutableData/CardMasterRequest.cs
+++ b/SVSim.EmulatedEntrypoint/Models/Dtos/Requests/ImmutableData/CardMasterRequest.cs
@@ -14,5 +14,5 @@ public class CardMasterRequest : BaseRequest
 {
     [JsonPropertyName("card_master_hash")]
     [Key("card_master_hash")]
-    public string? CardMasterHash { get; set; }
+    public string CardMasterHash { get; set; } = "";
 }