diff --git a/ChangeLog b/ChangeLog
index 2a6143a7f4..e9df09fd9b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Jun 22 06:05:36 2013  Koichi Sasada  <ko1@atdot.net>
+
+	* gc.c (rb_gc_giveup_promoted_writebarrier): remove `rest_sweep()'
+	  because all of remembered objects are called for gc_mark_children().
+
 Sat Jun 22 05:08:03 2013  Koichi Sasada  <ko1@atdot.net>
 
 	* gc.c (rgengc_rememberset_mark): call gc_mark_children() for
diff --git a/gc.c b/gc.c
index 87ac7d50d8..85fb9e41c8 100644
--- a/gc.c
+++ b/gc.c
@@ -3806,13 +3806,6 @@ rb_gc_giveup_promoted_writebarrier(VALUE obj)
     rgengc_report(2, objspace, "rb_gc_giveup_writebarrier: %p (%s)%s\n", (void *)obj, obj_type_name(obj),
 		  rgengc_remembered(objspace, obj) ? " (already remembered)" : "");
 
-    /* need to sweep all slots before demote */
-    /* TODO: check delayed sweeping slot or not
-     *       if delayed sweepling slot, then mark it
-     *       else demote simple
-     */
-    rest_sweep(objspace);
-
     RVALUE_DEMOTE(obj);
     rgengc_remember(objspace, obj);