diff --git a/ChangeLog b/ChangeLog
index 496159baea..6f93547ceb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Dec  3 20:18:46 2013  Narihiro Nakamura  <authornari@gmail.com>
+
+	* object.c (rb_obj_clone): Protect FL_PROMOTED and FL_WB_PROTECTED
+	  flags of a destination object.
+
 Tue Dec  3 20:16:38 2013  Masaki Matsushita  <glass.saga@gmail.com>
 
 	* array.c (rb_hash_rehash): use hash_alloc() instead of rb_hash_new().
diff --git a/object.c b/object.c
index 70f6d66e5e..f316a1bcbe 100644
--- a/object.c
+++ b/object.c
@@ -335,7 +335,7 @@ rb_obj_clone(VALUE obj)
         rb_raise(rb_eTypeError, "can't clone %s", rb_obj_classname(obj));
     }
     clone = rb_obj_alloc(rb_obj_class(obj));
-    RBASIC(clone)->flags &= FL_TAINT;
+    RBASIC(clone)->flags &= (FL_TAINT|FL_PROMOTED|FL_WB_PROTECTED);
     RBASIC(clone)->flags |= RBASIC(obj)->flags & ~(FL_PROMOTED|FL_FREEZE|FL_FINALIZE);
 
     singleton = rb_singleton_class_clone_and_attach(obj, clone);