May I suggest the following patch to slime-open-stream-to-lisp: --- slime.el 30 Dec 2005 19:26:22 +0100 1.574 +++ slime.el 30 Dec 2005 22:58:49 +0100 @@ -2775,9 +2775,8 @@ (list* '("<" . slime-mark-presentation-start-handler) '(">" . slime-mark-presentation-end-handler) bridge-handlers))) - (set-process-coding-system stream - slime-net-coding-system - slime-net-coding-system) + (let ((pcs (process-coding-system (slime-current-connection)))) + (set-process-coding-system stream (car pcs) (cdr pcs))) (when-let (secret (slime-secret)) (slime-net-send secret stream)) stream)) It appears to solve the following problem. I have not changed slime-net-coding-system from its default value, but I have (setf slime-lisp-implementations '((sbcl ("sbcl") :coding-system utf-8-unix) (cmucl ("cmucl") :coding-system iso-latin-1-unix))) So when I run sbcl, coding systems on the emacs and sbcl sides match for input and printing of values, but there is a mismatch on printing from lisp code: The sbcl side uses utf-8, while the emacs side assumes latin-1. Quick demo (first good, second bad): cl-user> #\å #\å cl-user> (format t "~C" #\å) Ã¥ nil - Harald