ASP.NET MVC5 EF6 Relation with ApplicationUser

[ForeignKey("Creator")]
public string CreatorID {get;set;}
public virtual ApplicationUser Creator {get;set;}

While update-database, errors appeared. Said there's no Key column for ApplicationUser, I've got information about modelBuilder, but I don't want to change anything inside the project and database, which project using Asp.net default authentication template and database column with AspNet prefix. Is there any ways to get there Thanks