commit 21a2010bf2768bc658e09666c2135063ce004efc
Author: Armin Ronacher <armin.ronacher@active-4.com>
Date:   Sun Sep 16 08:30:50 2012 +0900

    Fixed an unicode error after 2to3

diff --git a/jinja2/environment.py b/jinja2/environment.py
index 130f9a1..1b5dc40 100644
--- a/jinja2/environment.py
+++ b/jinja2/environment.py
@@ -572,7 +572,7 @@ class Environment(object):
 
             # Python 3.3 added a source filesize to the header
             if sys.version_info >= (3, 3):
-                py_header += '\x00\x00\x00\x00'
+                py_header += u'\x00\x00\x00\x00'.encode('iso-8859-15')
 
         def write_file(filename, data, mode):
             if zip: