diff --git a/txdatadog/client.py b/txdatadog/client.py
index 09459cf..61baa94 100644
--- a/txdatadog/client.py
+++ b/txdatadog/client.py
@@ -5,7 +5,7 @@
 import attr
 
 
-@attr.s
+@attr.s(hash=True)
 class DogStatxD(DatagramProtocol, object):
 
     host = attr.ib(default="127.0.0.1")
diff --git a/txdatadog/metrics.py b/txdatadog/metrics.py
index 20c23e9..4bfc0bc 100644
--- a/txdatadog/metrics.py
+++ b/txdatadog/metrics.py
@@ -10,7 +10,7 @@ class NoValueSpecified(Exception):
     """
 
 
-@attr.s
+@attr.s(hash=True)
 class _Metric(object):
 
     name = attr.ib()
@@ -34,7 +34,7 @@ def with_value(self, value):
         )
 
 
-@attr.s
+@attr.s(hash=True)
 class _ValuedMetric(object):
 
     name = attr.ib()
diff --git a/txdatadog/tests/fakes.py b/txdatadog/tests/fakes.py
index 95bb5c7..1176701 100644
--- a/txdatadog/tests/fakes.py
+++ b/txdatadog/tests/fakes.py
@@ -30,7 +30,7 @@ def connect(self, host, port):
         self.connected = True
 
 
-@attr.s
+@attr.s(hash=True)
 class Server(object):
     """
     A DogStatsD server.