diff --git a/ChangeLog b/ChangeLog
index 3a2dd64585..7d7c3b66f2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Wed Nov 27 15:12:55 2013  Koichi Sasada  <ko1@atdot.net>
+
+	* gc.c (gc_page_sweep): disable debug print.
+
 Wed Nov 27 15:05:59 2013  Koichi Sasada  <ko1@atdot.net>
 
 	* gc.c (gc_stat): add new information heap_eden_page_length and
diff --git a/gc.c b/gc.c
index 0f10ceb933..290849479b 100644
--- a/gc.c
+++ b/gc.c
@@ -2742,7 +2742,7 @@ gc_page_sweep(rb_objspace_t *objspace, rb_heap_t *heap, struct heap_page *sweep_
     heap_pages_final_slots += final_slots;
     sweep_page->final_slots = final_slots;
 
-    if (1) fprintf(stderr, "gc_page_sweep(%d): freed?: %d, limt: %d, freed_slots: %d, empty_slots: %d, final_slots: %d\n",
+    if (0) fprintf(stderr, "gc_page_sweep(%d): freed?: %d, limt: %d, freed_slots: %d, empty_slots: %d, final_slots: %d\n",
 		   (int)rb_gc_count(),
 		   final_slots + freed_slots + empty_slots == sweep_page->limit,
 		   (int)sweep_page->limit, (int)freed_slots, (int)empty_slots, final_slots);