Suppose I have 2 windows, 1 for Lisp code, another showing the REPL. Every time I C-xC-e in the Lisp-code buffer, it jerks downwards so that the current line (at point) becomes the last visible line in the window. This is because slime is attempting a (recenter -1), but with the wrong window. I have an older Emacs 21.4.1 here which doesn't have with-selected-window (a macro). The current (the last time I checked) "emulation" of with-selected-window defines a function instead of a macro. This causes evaluation of its body form at the wrong time/places. See eg slime-repl-show-maximum-output (the original source of my investigations and hence the subject of this email). Perhaps a macro equivalent to slime-defun-if-undefined could be used instead? Something like... ;; here, fboundp substitutes for macro-boundp (defmacro slime-defmacro-if-undefined (name &rest rest) `(unless (fboundp ',name) (defmacro ,name ,@rest))) Cheers!