LINQ lambda - convert int to string

i'm trying to compare a int with a string in the join method of linq lambda, like this:

database.booking.Join(database.address,
                      book => book.bookno,
                      afh => afh.addressid.ToString(),
                       (book, afh) => new { booking = book, add = afh })
                .Where(book => book.address.name == "test");

but i'm getting an error on the ToString():

System.NotSupportedException: LINQ to Entities does not recognize the method 'Int32 ToInt32(System.String)' method, and this method cannot be translated into a store expression.

How do i solve this?