diff --git a/ChangeLog b/ChangeLog
index 461d21fe26..2c353a8a10 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Jun 10 16:22:50 2013  Koichi Sasada  <ko1@atdot.net>
+
+	* array.c (rb_ary_new_from_values): add assertion
+	  (ary should be young object).
+
 Mon Jun 10 16:05:59 2013  Koichi Sasada  <ko1@atdot.net>
 
 	* gc.c (wmap_mark): check allocation of `w->obj2wmap'.
diff --git a/array.c b/array.c
index 345a60bfc6..7f423ed3bb 100644
--- a/array.c
+++ b/array.c
@@ -456,6 +456,7 @@ rb_ary_new_from_values(long n, const VALUE *elts)
 
     ary = rb_ary_new2(n);
     if (n > 0 && elts) {
+	assert(!OBJ_PROMOTED(obj));
 	RARRAY_PTR_USE(ary, ptr, {
 	    MEMCPY(ptr, elts, VALUE, n); /* new array is not old gen */
 	});