diff --git a/letsencrypt/client/client.py b/letsencrypt/client/client.py
index dd4e23c6e..0100f4f4a 100644
--- a/letsencrypt/client/client.py
+++ b/letsencrypt/client/client.py
@@ -59,7 +59,6 @@ class Client(object):
         :type dv_auth: :class:`letsencrypt.client.interfaces.IAuthenticator`
 
         """
-        sanity_check_names([server])
         self.network = network.Network(server)
         self.authkey = authkey
 
diff --git a/letsencrypt/client/network.py b/letsencrypt/client/network.py
index 135349c41..82c98c363 100644
--- a/letsencrypt/client/network.py
+++ b/letsencrypt/client/network.py
@@ -17,13 +17,12 @@ logging.getLogger("requests").setLevel(logging.WARNING)
 class Network(object):
     """Class for communicating with ACME servers.
 
-    :ivar str server: Certificate authority server
+    :ivar str server: Certificate authority server (server[:port])
     :ivar str server_url: Full URL of the CSR server
 
     """
     def __init__(self, server):
-        self.server = server
-        self.server_url = "https://%s/acme/" % self.server
+        self.server_url = "https://%s/acme/" % server
 
     def send(self, msg):
         """Send ACME message to server.