diff --git a/ChangeLog b/ChangeLog
index ce179579b6..44d8723bdc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Dec 15 23:48:39 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* thread.c (sleep_timeval): cast tv_usec to long to shut up
+	  warnings on OSX.  [ruby-dev:37449]
+
 Mon Dec 15 23:34:04 2008  Tanaka Akira  <akr@fsij.org>
 
 	* ext/pty/pty.c (pty_open): set FMODE_SYNC and FMODE_DUPLEX.
diff --git a/thread.c b/thread.c
index 4ab0788534..c154c057b6 100644
--- a/thread.c
+++ b/thread.c
@@ -805,8 +805,8 @@ sleep_timeval(rb_thread_t *th, struct timeval tv)
 	if (to.tv_sec < tvn.tv_sec) break;
 	if (to.tv_sec == tvn.tv_sec && to.tv_usec <= tvn.tv_usec) break;
 	thread_debug("sleep_timeval: %ld.%.6ld > %ld.%.6ld\n",
-		     (long)to.tv_sec, to.tv_usec,
-		     (long)tvn.tv_sec, tvn.tv_usec);
+		     (long)to.tv_sec, (long)to.tv_usec,
+		     (long)tvn.tv_sec, (long)tvn.tv_usec);
 	tv.tv_sec = to.tv_sec - tvn.tv_sec;
 	if ((tv.tv_usec = to.tv_usec - tvn.tv_usec) < 0) {
 	    --tv.tv_sec;