1 files changed, 4 insertions, 3 deletions
diff --git a/object.c b/object.c
index 6f4b1239c8..c70ce4978e 100644
--- a/object.c
+++ b/object.c
@@ -354,14 +354,15 @@ rb_obj_clone2(int argc, VALUE *argv, VALUE obj)
 	rb_get_kwargs(opt, keyword_ids, 0, 1, kwargs);
 	kwfreeze = kwargs[0];
 	if (kwfreeze != Qundef && kwfreeze != Qtrue && kwfreeze != Qfalse) {
-	    rb_raise(rb_eArgError, "unexpected value for freeze: %s",
-		     rb_builtin_class_name(kwfreeze));
+	    rb_raise(rb_eArgError, "unexpected value for freeze: %"PRIsVALUE,
+		     rb_obj_class(kwfreeze));
 	}
     }
 
     if (special_object_p(obj)) {
 	if (kwfreeze == Qfalse)
-	    rb_raise(rb_eArgError, "can't unfreeze %s", rb_obj_classname(obj));
+	    rb_raise(rb_eArgError, "can't unfreeze %"PRIsVALUE,
+		     rb_obj_class(obj));
 	return obj;
     }
     clone = rb_obj_alloc(rb_obj_class(obj));