WireInputData in bind_param -> PHP Notice: Indirect modification of overloaded property ... has no effect

[theo]

Hello

In Debug Mode i am getting this notice:

Quote

Notice: Indirect modification of overloaded property ProcessWire\WireInputData::$Anrede has no effect etc...

  $stmt->bind_param("sssssssssssiis", $input->whitelist->Anrede, $input->whitelist->Vorname, $input->whitelist->Name,
  $input->whitelist->Firma, $input->whitelist->Adresse, $input->whitelist->Adresse_Zusatz, $input->whitelist->PLZ, ....)

It's working afaics, but showing this notice.

What can I do about it (Except turn Debug Mode off)?

Thank you.