Hello, I compiled ecl16.0.0 with option "--with-cxx". Then I use ffi:defcallback function like (ffi:defcallback yyyy :void () ..... ) then compile-file (compile-file "xxxxx.lisp" :c-file "xxxxx.cpp" :system-p t) I received error message as follows (freebsd10.1 clang++) xxxxx.cpp:162:8: error: no matching function for call to 'ecl_make_foreign_data' T0 = ecl_make_foreign_data(ECL_SYM("POINTER-VOID",1381),0,ecl_callback_0) I try as follows in src/cmp/cmpcbk.lsp & src/new-cmp/cmpc-cbk.lsp line 44 from: ,(format nil "ecl_make_foreign_data(@':pointer-void,0,~a)" c-name) to: ,(format nil "ecl_make_foreign_data(@':pointer-void,0,(void*)~a)" c-name) after that, I did not receive error message and ffi:callback work fine. Would you let me know what your thoughts are on this matter. hirohiro447