I was having trouble running the example in the documents: (foreign-funcall-pointer (foreign-symbol-pointer "abs") :int -42 :int) I got SIMPLE-ERROR: Unknown CFFI type: 4. I was going crazy, until i searched google code and found this working example: http://www.google.com/codesearch/p?hl=en#wVc2UuwHR3k/trunk/tree/resolve.lisp&q=foreign-funcall-pointer%20lang:lisp Retrying with an added "()" before the arg list works. foreign-funcall-pointer (foreign-symbol-pointer "abs") () :int -42 :int) works ! This allows one to call a defcallback function from lisp making the following unnecessary in the documentation of defcallback "The macro defcallback defines a Lisp function the can be called from C (but not from Lisp)." because the following works: (defcallback fx :int ((x :int)) (progn (print "test") 3)) (foreign-funcall-pointer (callback fx) () :int 4 :int) Thanks for the cffi, Naveen