[NTG-context] semi-smart quotes in verbatim text?

This is puzzling me. If i type this in a text editor: \starttext These are 'quotes'. \starttyping let a = 'quoted string' \stoptyping \stoptext I'm using dumb quotes (hex 27). ConText renders this as this: These are ’quotes’. let a = ’quoted string’ ie the quotes have been educated - although only half-educated, since the opening one should be an opening one, if you see what I mean. But I really don't want characters in the verbatim (typing) section to change...because when you copy them from the PDF into an editor, the code listings don't work! There must be some kind of switch somewhere that stops ConteXt changing them? thanks for any help