diff -r 49017c391564 Lib/multiprocessing/pool.py
--- a/Lib/multiprocessing/pool.py	Wed Mar 19 10:07:26 2014 +0000
+++ b/Lib/multiprocessing/pool.py	Wed Mar 19 07:46:32 2014 -0700
@@ -56,7 +56,7 @@
     def __str__(self):
         return self.tb
 
-class ExceptionWithTraceback:
+class ExceptionWithTraceback(Exception):
     def __init__(self, exc, tb):
         tb = traceback.format_exception(type(exc), exc, tb)
         tb = ''.join(tb)