diff --git a/zerver/lib/timeout.py b/zerver/lib/timeout.py
index 3da3e9e409..285ced1b7c 100644
--- a/zerver/lib/timeout.py
+++ b/zerver/lib/timeout.py
@@ -4,6 +4,7 @@ import sys
 import time
 import ctypes
 import threading
+import six
 
 # Based on http://code.activestate.com/recipes/483752/
 
@@ -79,5 +80,5 @@ def timeout(timeout, func, *args, **kwargs):
     if thread.exc_info:
         # Raise the original stack trace so our error messages are more useful.
         # from http://stackoverflow.com/a/4785766/90777
-        raise thread.exc_info[0], thread.exc_info[1], thread.exc_info[2]
+        six.reraise(thread.exc_info[0], thread.exc_info[1], thread.exc_info[2])
     return thread.result