Fix argument specs to `Exception`
@@ -594,7 +594,7 @@ mrb_init_exception(mrb_state *mrb)
mrb->eException_class = exception = mrb_define_class(mrb, "Exception", mrb->object_class); /* 15.2.22 */
MRB_SET_INSTANCE_TT(exception, MRB_TT_EXCEPTION);
mrb_define_class_method(mrb, exception, "exception", mrb_instance_new, MRB_ARGS_OPT(1));
- mrb_define_method(mrb, exception, "exception", exc_exception, MRB_ARGS_ANY());
+ mrb_define_method(mrb, exception, "exception", exc_exception, MRB_ARGS_OPT(1));
mrb_define_method(mrb, exception, "initialize", exc_initialize, MRB_ARGS_OPT(1));
mrb_define_method(mrb, exception, "to_s", exc_to_s, MRB_ARGS_NONE());
mrb_define_method(mrb, exception, "message", exc_message, MRB_ARGS_NONE());
