diff --git a/ChangeLog b/ChangeLog
index ceec46015d..ae8062cb9c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Jun 13 21:41:05 2011  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* thread_win32.c (native_cond_signal): remove unnecessary rb_bug().
+	  It's addional fix for r32021. [Bug #4696]
+
 Mon Jun 13 20:50:49 2011  Martin Bosslet  <Martin.Bosslet@googlemail.com>
 
 	* test/openssl/test_ec.rb
diff --git a/thread_win32.c b/thread_win32.c
index 694b1e1f87..c0a026c7b6 100644
--- a/thread_win32.c
+++ b/thread_win32.c
@@ -414,9 +414,6 @@ native_cond_signal(rb_thread_cond_t *cond)
 
 	SetEvent(e->event);
     }
-    else {
-	rb_bug("native_cond_signal: no pending threads");
-    }
 }
 
 static void