I found two places where EQ was used when comparing numbers. The following patch replaces each occurrence with EQL. Ariel --- headers.lisp~ 2008-02-13 18:02:17.000000000 +0200 +++ headers.lisp 2008-02-25 02:31:03.000000000 +0200 @@ -105,7 +105,7 @@ ;; is no content) (or chunkedp head-request-p - (eq (return-code) +http-not-modified+) + (eql (return-code) +http-not-modified+) (content-length) content))) ;; now set headers for keep-alive and chunking --- server.lisp~ 2008-02-13 18:02:18.000000000 +0200 +++ server.lisp 2008-02-25 02:31:16.000000000 +0200 @@ -420,7 +420,7 @@ backtrace))))) (with-debugger ;; skip dispatch if bad request - (when (eq (return-code) +http-ok+) + (when (eql (return-code) +http-ok+) ;; now do the work (dispatch-request *dispatch-table*))))) (when error