diff --git a/lib/timeout.rb b/lib/timeout.rb
index ad951d2..642114f 100644
--- a/lib/timeout.rb
+++ b/lib/timeout.rb
@@ -67,7 +67,8 @@ module Timeout
     return yield(sec) if sec == nil or sec.zero?
     message = "execution expired"
     e = Error
-    bt = catch((klass||ExitException).new) do |exception|
+    klass ||= ExitException
+    bt = catch(klass.new(message)) do |exception|
       begin
         x = Thread.current
         y = Thread.start {
@@ -76,11 +77,11 @@ module Timeout
           rescue => e
             x.raise e
           else
-            x.raise exception, message
+            x.raise exception
           end
         }
         return yield(sec)
-      rescue (klass||ExitException) => e
+      rescue klass => e
         e.backtrace
       ensure
         if y