diff --git a/puz.py b/puz.py
index <HASH>..<HASH> 100644
--- a/puz.py
+++ b/puz.py
@@ -5,7 +5,7 @@ import string
 import struct
 import sys
 
-PY3 = sys.version_info[0] == 3
+PY3 = sys.version_info[0] >= 3
 
 if PY3:
     str = str
Let's assume these changes will make it through to Python 4