Thanks for looking into this, Ludo. At first glance, I'd say that this is not a compilation option but the way strings are encoded by default. It seems that multibyte encoding is used all over the place by a few compilers including SBCL (and CCL I think). One way I know around this (I'm by no mean a Common Lisp expert) is the flexi-streams package for re-encoding. More generally, shouldn't we make the reference scanner a bit smarter? In particular, how does it handle non-ASCII references? Maybe it would not be unreasonable to handle UTF-8 and UCS-4 for instance? -- Pierre Neidhardt https://ambrevar.xyz/