diff --git a/ChangeLog b/ChangeLog
index d22415931a..8fa08a2cd7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Nov  1 17:25:30 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* gc.c (is_live_object): finalizer may not run because of lazy-sweep.
+	  [ruby-dev:47786] [Bug #9069]
+
 Fri Nov  1 16:55:52 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* string.c (rb_str_scrub): export with fixed length arguments, and
diff --git a/gc.c b/gc.c
index 93b15882d1..2f261b3037 100644
--- a/gc.c
+++ b/gc.c
@@ -2050,7 +2050,10 @@ is_dead_object(rb_objspace_t *objspace, VALUE ptr)
 static inline int
 is_live_object(rb_objspace_t *objspace, VALUE ptr)
 {
-    if (BUILTIN_TYPE(ptr) == 0) return FALSE;
+    switch (BUILTIN_TYPE(ptr)) {
+      case 0: case T_ZOMBIE:
+	return FALSE;
+    }
     if (RBASIC(ptr)->klass == 0) return FALSE;
     if (is_dead_object(objspace, ptr)) return FALSE;
     return TRUE;