Create a hierarchical foreign key to Identity 3 ApplicationUser:IdentityUser

Question

I am using Identity 3 in ASP.NET 5 RC1/Core

I need to create a foreign key reference in the ApplicationUser that refers to the primary key of the ApplicationUser(IdentityUser) using EF Code First.

I have tried

public class ApplicationUser : IdentityUser
{
    [Column("fk_LineManagerUserId")]
    public Guid LineManagerUserId { get; set; }
    [ForeignKey("LineManagerUserId")]
    public virtual ApplicationUser LineManagerUser { get; set; }
}

or

public class ApplicationUser : IdentityUser
{
    [Column("fk_LineManagerUserId")]
    public string LineManagerUserId { get; set; }
    [ForeignKey("LineManagerUserId")]
    public virtual ApplicationUser LineManagerUser { get; set; }
}

but I get

Introducing FOREIGN KEY constraint 'FK_ApplicationUser_ApplicationUser_LineManagerUserId' on table 'AspNetUs ers' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.