diff --git a/apitools/base/protorpclite/messages.py b/apitools/base/protorpclite/messages.py
index 0d564e91..6a1fef2f 100644
--- a/apitools/base/protorpclite/messages.py
+++ b/apitools/base/protorpclite/messages.py
@@ -758,6 +758,8 @@ class Order(Message):
 
     """
 
+    __hash__ = None
+
     def __init__(self, **kwargs):
         """Initialize internal messages state.