Convertir Web application con basic authentication a claims authentication

$webappname = read-host "Ingrese la url del Web Application"
$wa = Get-SPWebApplication $webappname
$wa.UseClaimsAuthentication = $True
$wa.Update()
$account = read-host "Ingrese Policy Account"
$account = (New-SPClaimsPrincipal –Identity $account –IndentityType 1).ToEncodedString()
$zp = $wa.ZonePolicies("Default")
$p = $zp.Add($account,"PSPolicy")
$fc = $wa.PolicyRoles.GetSPecialRole("FullControl")
$p.PolicyRoleBindings.Add($fc)
$wa.Update()
$wa.MigrateUsers($True)
$wa.ProvisionGlobally()