diff --git a/nl80211.py b/nl80211.py
index 6aaeeab..2e93dae 100755
--- a/nl80211.py
+++ b/nl80211.py
@@ -248,24 +248,33 @@ class GenericNetlink(object):
     7: ('mcast_groups', Array(_mcast_grp_attr)),
   })
 
-  _msgtypes = {
-    'nlctrl': [_ctrl_attr, 0x10],
-  }
+  _msgtypes = [
+    [0x10, 'nlctrl', _ctrl_attr],
+  ]
 
   CTRL_CMD_NEWFAMILY = 0x01
   CTRL_CMD_GETFAMILY = 0x03
 
   def __init__(self):
     self._netlink = Netlink()
+    self._UpdateMsgTypes()
     self.Send('nlctrl', self._netlink.NLMSG_F_DUMP, self.CTRL_CMD_GETFAMILY, 1, '')
     for msg in self.Recv():
       msgtype, attrs = msg
       assert msgtype == self.CTRL_CMD_NEWFAMILY, msgtype
       family_name = attrs['family_name'].rstrip('\0')
-      self._msgtypes.setdefault(family_name, [None, None])[1] = attrs['family_id']
+      if family_name in self._msgtypes_by_name:
+        assert attrs['family_id'] == self._msgtypes_by_name[family_name][0], attrs['family_id']
+      else:
+        self._msgtypes.append([attrs['family_id'], family_name, None])
+    self._UpdateMsgTypes()
+
+  def _UpdateMsgTypes(self):
+    self._msgtypes_by_id = dict((i[0], i) for i in self._msgtypes)
+    self._msgtypes_by_name = dict((i[1], i) for i in self._msgtypes)
 
   def RegisterMsgType(self, family_name, parser):
-    self._msgtypes[family_name][0] = parser
+    self._msgtypes_by_name[family_name][2] = parser
 
   def Send(self, msgtype, flags, cmd, version, msg):
     accumulator = Accumulator()
@@ -275,13 +284,13 @@ class GenericNetlink(object):
       version=version,
       reserved=0)
     accumulator.Append(msg)
-    msgtype_id = self._msgtypes[msgtype][1]
+    msgtype_id = self._msgtypes_by_name[msgtype][0]
     self._netlink.Send(msgtype_id, flags, str(accumulator))
 
   def Recv(self):
     for msgtype, iterator in self._netlink.Recv():
       genlhdr = self._genlmsghdr.Unpack(iterator)
-      parser = [v[0] for v in self._msgtypes.itervalues() if v[1] == msgtype][0]
+      parser = self._msgtypes_by_id[msgtype][2]
       yield (genlhdr['cmd'], parser.Unpack(iterator))