Use \r or \x0d? http://caml.inria.fr/pub/docs/manual-ocaml/lex.html David On 5 Aug 2013, at 18:34, "r.3@libertysurf.fr" > wrote: Dear list, I got a new error with trunk version of ocaml. I have in a module a code that appears like that in emacs (which is used to convert files from dos to unix) : String.get s (String.length s -1) = '^M' The thing is that '^M' is actually the return character of windows (RET) This works with ocaml 4.00, but now, with trunk version of ocaml, it tells me this is a "syntax error". How shall I do ? what is supposed to be inside the ' ' ? The emacs command "describe-char" gives me this unicode : 0x0D Best regards, William