Hi, on second thought, I'm forwarding this to sbcl-devel because I think this might be a bug. The same scenario works fine with CCL. CMUCL gives a note and a warning but still works: CL-USER> (test 'a 'b) ; In: TEST 'A ; (TEST 'A 'B) ; ==> ; (LET (#) ; (SETQ #:G0 #) ; #:G0) ; Note: Variable LISP::BACKQ-COMMA defined but never used. ; ; ; Warning: These variables are undefined: ; #:G0 OBJ ; (A B) The macroepansion is however similar to that of SBCL: CL-USER> (macroexpand '(test 'a 'b)) (LET ((LISP::BACKQ-COMMA OBJ)) (SETQ #:G4368 (LIST 'A 'B)) #:G4368) T -- Resistance is futile. You will be jazzimilated. Lisp, Jazz, Aïkido: http://www.didierverna.info