diff --git a/ChangeLog b/ChangeLog
index 1126767e6e..524a84c908 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Apr 19 12:46:15 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/timeout.rb (Timeout#timeout): propagate errors to the
+	  caller.  [ruby-dev:41010]'
+
 Mon Apr 19 00:27:03 2010  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* vm_method.c (rb_add_method_def): workarond fix for redefinition
diff --git a/lib/timeout.rb b/lib/timeout.rb
index 1dccc57477..297b76936c 100644
--- a/lib/timeout.rb
+++ b/lib/timeout.rb
@@ -46,8 +46,13 @@ module Timeout
     begin
       x = Thread.current
       y = Thread.start {
-        sleep sec
-        x.raise exception, "execution expired" if x.alive?
+        begin
+          sleep sec
+        rescue => e
+          x.raise e
+        else
+          x.raise exception, "execution expired" if x.alive?
+        end
       }
       return yield(sec)
     rescue exception => e