diff --git a/ChangeLog b/ChangeLog
index 7f3caf747a..6d4b446ef0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Dec  1 03:38:04 2012  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* lib/thread.rb (ConditionVariable#broadcast): s/RuntimeError/StandardError/
+	* lib/thread.rb (ConditionVariable#signal): ditto.
+
 Sat Dec  1 03:29:52 2012  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* lib/thread.rb (SizedQueue#pop): rewrite by using ConditionVariable.
diff --git a/lib/thread.rb b/lib/thread.rb
index e3aeed19fe..47add67e89 100644
--- a/lib/thread.rb
+++ b/lib/thread.rb
@@ -84,7 +84,7 @@ class ConditionVariable
   # Wakes up the first thread in line waiting for this lock.
   #
   def signal
-    Thread.async_interrupt_timing(RuntimeError => :on_blocking) do
+    Thread.async_interrupt_timing(StandardError => :on_blocking) do
       begin
         t = @waiters_mutex.synchronize {@waiters.shift}
         t.run if t
@@ -99,7 +99,7 @@ class ConditionVariable
   # Wakes up all threads waiting for this lock.
   #
   def broadcast
-    Thread.async_interrupt_timing(RuntimeError => :on_blocking) do
+    Thread.async_interrupt_timing(StandardError => :on_blocking) do
       waiters0 = nil
       @waiters_mutex.synchronize do
         waiters0 = @waiters.dup