diff --git a/ChangeLog b/ChangeLog
index d62def0b36..902a80b433 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu May  6 17:16:42 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* time.c (rb_localtime_r2): get rid of infinite loop bug of
+	  localtime() on x86_64-darwin.  [ruby-core:30031]
+
 Thu May  6 15:56:12 2010  Aaron Patterson <aaron@tenderlovemaking.com>
 
 	* ext/fiddle/*: Adding fiddle library to wrap libffi
diff --git a/time.c b/time.c
index f6d0f3a7cb..62e4235603 100644
--- a/time.c
+++ b/time.c
@@ -863,6 +863,9 @@ rb_localtime_r(const time_t *tp, struct tm *result)
 static struct tm *
 rb_localtime_r2(const time_t *t, struct tm *result)
 {
+#if defined __APPLE__ && defined __LP64__
+    if (*t != (time_t)(int)*t) return NULL;
+#endif
     result = rb_localtime_r(t, result);
 #if defined(HAVE_MKTIME) && defined(LOCALTIME_OVERFLOW_PROBLEM)
     if (result) {