Error converting BigInt to integer using lambda

In the database the type is BigInt and in C # I am trying to convert to int and it can convert, but when it arrives in the lambda statement, it gives error.

 long codpro = Int64.Parse(tb_CodigoProduto.Text.Substring(0,14));
 db = (from p in data.Produtos where p.ProCodInt == codpro select p).FirstOrDefault();