diff --git a/EntityFrameworkCore.Domain/BaseDomainModel.cs b/EntityFrameworkCore.Domain/BaseDomainModel.cs
index 0a7ea84..5aa641c 100644
--- a/EntityFrameworkCore.Domain/BaseDomainModel.cs
+++ b/EntityFrameworkCore.Domain/BaseDomainModel.cs
@@ -5,6 +5,6 @@ public abstract class BaseDomainModel
   public int Id { get; set; } // Anything called "Id" is automatically a Primary Key.
   public DateTime CreatedDate { get; set;}
   public DateTime ModifiedDate { get; set;}
-  public string CreatedBy { get; set; }
-  public string ModifiedBy { get; set; }
+  public string? CreatedBy { get; set; }
+  public string? ModifiedBy { get; set; }
 }