UnicodeEncodeError with pdftext --out_path

[jordi-z80]

I'm getting the following error on some PDFs, only when using pdftext --out_path to write to a file on Windows:

UnicodeEncodeError: 'charmap' codec can't encode characters in position 656-657: character maps to

Probably a wrong encoding when opening the file to write, would be nice to have an option to create that file in utf-8 mode.

Thanks!