diff --git a/os_ken/lib/rpc.py b/os_ken/lib/rpc.py
index 5381ef99..5ff2d531 100644
--- a/os_ken/lib/rpc.py
+++ b/os_ken/lib/rpc.py
@@ -39,7 +39,12 @@ class MessageEncoder(object):
 
     def __init__(self):
         super(MessageEncoder, self).__init__()
-        self._packer = msgpack.Packer(use_bin_type=True)
+        # NOTE(ralonsoh): msgpack>=1.0.0
+        self._packer = msgpack.Packer()
+        # The strict_map_key=False option is required to use int keys in
+        # maps; it is disabled by default to prevent hash collision denial
+        # of service attacks (hashdos) in scenarios where an attacker can
+        # control the keys to be hashed.
         self._unpacker = msgpack.Unpacker(strict_map_key=False)
         self._next_msgid = 0
 
diff --git a/os_ken/services/protocols/bgp/net_ctrl.py b/os_ken/services/protocols/bgp/net_ctrl.py
index eb516c18..418486ca 100644
--- a/os_ken/services/protocols/bgp/net_ctrl.py
+++ b/os_ken/services/protocols/bgp/net_ctrl.py
@@ -101,8 +101,13 @@ class RpcSession(Activity):
     def __init__(self, sock, outgoing_msg_sink_iter):
         self.peer_name = str(sock.getpeername())
         super(RpcSession, self).__init__(self.NAME_FMT % self.peer_name)
-        self._packer = msgpack.Packer(encoding='utf-8', use_bin_type=True)
-        self._unpacker = msgpack.Unpacker(encoding='utf-8')
+        # NOTE(ralonsoh): msgpack>=1.0.0
+        self._packer = msgpack.Packer()
+        # The strict_map_key=False option is required to use int keys in
+        # maps; it is disabled by default to prevent hash collision denial
+        # of service attacks (hashdos) in scenarios where an attacker can
+        # control the keys to be hashed.
+        self._unpacker = msgpack.Unpacker(strict_map_key=False)
         self._next_msgid = 0
         self._socket = sock
         self._outgoing_msg_sink_iter = outgoing_msg_sink_iter