diff --git a/pylibmc.py b/pylibmc.py
index 3d98816..e5113cb 100644
--- a/pylibmc.py
+++ b/pylibmc.py
@@ -57,9 +57,9 @@ class BehaviorDict(dict):
         super(BehaviorDict, self).__setitem__(name, value)
         self.client.set_behaviors({name: value})
 
-    def update(self, *args, **kwds):
-        super(BehaviorDict, self).update(*args, **kwds)
-        self.client.set_behaviors(self.copy())
+    def update(self, d):
+        super(BehaviorDict, self).update(d)
+        self.client.set_behaviors(d.copy())
 
 class Client(_pylibmc.client):
     def __init__(self, servers, binary=False):
@@ -115,9 +115,9 @@ class Client(_pylibmc.client):
         This also happens for `distribution`.
         """
         behaviors = behaviors.copy()
-        if behaviors.get("hash", None) in hashers:
+        if behaviors.get("hash") is not None:
             behaviors["hash"] = hashers[behaviors["hash"]]
-        if behaviors.get("distribution") in distributions:
+        if behaviors.get("distribution") is not None:
             behaviors["distribution"] = distributions[behaviors["distribution"]]
         return super(Client, self).set_behaviors(behaviors)
 
diff --git a/tests.py b/tests.py
index 0c38e41..0f11b70 100644
--- a/tests.py
+++ b/tests.py
@@ -1,9 +1,11 @@
 """Tests. They want YOU!!
 
+
 Basic functionality.
 >>> _pylibmc.__version__ == pylibmc.__version__
 True
 >>> c = _pylibmc.client([test_server])
+>>> c.get("hello")
 >>> c.set("test_key", 123)
 True
 >>> c.get("test_key")
@@ -177,6 +179,14 @@ Empty server lists are bad for your health.
 Traceback (most recent call last):
   ...
 MemcachedError: empty server list
+
+Python-wrapped behaviors dict
+>>> pc = pylibmc.Client(["%s:%d" % test_server[1:]])
+>>> (pc.behaviors["hash"], pc.behaviors["distribution"])
+('default', 'modula')
+>>> pc.behaviors.update({"hash": "fnv1a_32", "distribution": "consistent"})
+>>> (pc.behaviors["hash"], pc.behaviors["distribution"])
+('fnv1a_32', 'consistent')
 """
 
 # Used to test pickling.