Entity Framework - case insensitive Contains?

I want a solution to this problem that does not involve ToUpper or ToLower, as I use in the code below;

var upper = term.ToUpper();
using (var db = this.DataContext)
{
    return db.Counties.Where(x => x.CountyName.ToUpper().Contains(upper)).ToList();
}

I am using entitly framework so the C# solution of using StringComparison.CurrentCultureIgnoreCase does not work. It does work for Equals, EndsWith and StartsWith, but not Contains.