When compiling with SBCL 1.0.49, discovered the dynamic-extent declaration at the end of this has two typos, where the dynamic extent is declared for #'continuation and #'constructor, rather than for the gensym'd names for them. So the second version of this code is with this issue fixed. (defmacro define-invoke-with (macro-name func-name record-type doc-string) `(defmacro ,macro-name ((stream &optional (record-type '',record-type) (record (gensym)) &rest initargs) &body body) ,doc-string (setq stream (stream-designator-symbol stream '*standard-output*)) (with-gensyms (constructor continuation) (multiple-value-bind (bindings m-i-args) (rebind-arguments initargs) `(let ,bindings (flet ((,constructor () (make-instance ,record-type ,@m-i-args)) (,continuation (,stream ,record) ,(declare-ignorable-form* stream record) ,@body)) (declare (dynamic-extent #'constructor #'continuation)) (,',func-name ,stream #',continuation ,record-type #',constructor ,@m-i-args))))))) ;;; here's the versioned with the repaired dynamic-extent declaration: (defmacro define-invoke-with (macro-name func-name record-type doc-string) `(defmacro ,macro-name ((stream &optional (record-type '',record-type) (record (gensym)) &rest initargs) &body body) ,doc-string (setq stream (stream-designator-symbol stream '*standard-output*)) (with-gensyms (constructor continuation) (multiple-value-bind (bindings m-i-args) (rebind-arguments initargs) `(let ,bindings (flet ((,constructor () (make-instance ,record-type ,@m-i-args)) (,continuation (,stream ,record) ,(declare-ignorable-form* stream record) ,@body)) (declare (dynamic-extent #',constructor #',continuation)) (,',func-name ,stream #',continuation ,record-type #',constructor ,@m-i-args)))))))