diff --git a/cloudmesh/common/default.py b/cloudmesh/common/default.py
index <HASH>..<HASH> 100644
--- a/cloudmesh/common/default.py
+++ b/cloudmesh/common/default.py
@@ -14,7 +14,7 @@ class Default(object):
         if filename is None:
             self.filename = path_expand("~/.cloudmesh/default-data")
 
-        self.data = shelve.open(self.filename, writeback=True)
+        self.data = shelve.open(self.filename, protocol=2, writeback=True)
         self.data.sync()
 
     def __getitem__(self, context_key):
new:usr: use pickle protocol to gurantee version compatibility between python 2 and 3