diff --git a/ChangeLog b/ChangeLog
index 398e0e6366..96f4e4e40b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Oct 24 12:23:58 2013  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* thread.c (rb_thread_terminate_all): add a comment why we need
+	  state check and call terminate_i again.
+
 Thu Oct 24 12:15:02 2013  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* thread.c (rb_thread_terminate_all): add a comment why infinite
diff --git a/thread.c b/thread.c
index 757fca203b..e501f78675 100644
--- a/thread.c
+++ b/thread.c
@@ -449,6 +449,11 @@ rb_thread_terminate_all(void)
 	}
 	TH_POP_TAG();
 
+	/*
+	 * When caught an exception (e.g. Ctrl+C), let's broadcast
+	 * kill request again to ensure killing all threads even
+	 * if they are blocked on sleep, mutex, etc.
+	 */
 	if (state) {
 	    goto retry;
 	}