Hi! I've found in OCaml manual how to call object's method without arguments. But I have no idea how to call method with some arguments. For example I have this OCaml code: external call_meth: < .. > -> unit = "call_a_meth" class a = object method foo x = print_endline x end;; and C code: CAMLprim value call_a_meth(value obj) { CAMLparam1(obj); CAMLlocal3(meth, meth2, arg1); meth = caml_get_public_method(obj, caml_hash_variant("foo") ) ; if (meth == 0) printf ("Fuck\n"); arg1 = Val_int(1); // caml_callback2(meth, obj, arg1); // segfault in this line meth2 = caml_callback(meth, obj); // no crash, but method's body is not being executed caml_callback(meth2, arg1); // segfault. CAMLreturn(Val_unit); } I've tested three variants of calling above, But I still can't call a method with parameters. Any ideas? Best wishes, Kakadu