diff --git a/libp2p/network/connection/net_connection_interface.py b/libp2p/network/connection/net_connection_interface.py
index c2c6285..e308ad6 100644
--- a/libp2p/network/connection/net_connection_interface.py
+++ b/libp2p/network/connection/net_connection_interface.py
@@ -7,7 +7,7 @@ from libp2p.stream_muxer.abc import IMuxedConn
 
 
 class INetConn(Closer):
-    conn: IMuxedConn
+    muxed_conn: IMuxedConn
 
     @abstractmethod
     async def new_stream(self) -> INetStream:
diff --git a/libp2p/network/connection/swarm_connection.py b/libp2p/network/connection/swarm_connection.py
index cf1dc9e..e25d75f 100644
--- a/libp2p/network/connection/swarm_connection.py
+++ b/libp2p/network/connection/swarm_connection.py
@@ -16,15 +16,15 @@ Reference: https://github.com/libp2p/go-libp2p-swarm/blob/04c86bbdafd390651cb2ee
 
 
 class SwarmConn(INetConn):
-    conn: IMuxedConn
+    muxed_conn: IMuxedConn
     swarm: "Swarm"
     streams: Set[NetStream]
     event_closed: asyncio.Event
 
     _tasks: List["asyncio.Future[Any]"]
 
-    def __init__(self, conn: IMuxedConn, swarm: "Swarm") -> None:
-        self.conn = conn
+    def __init__(self, muxed_conn: IMuxedConn, swarm: "Swarm") -> None:
+        self.muxed_conn = muxed_conn
         self.swarm = swarm
         self.streams = set()
         self.event_closed = asyncio.Event()
@@ -37,7 +37,7 @@ class SwarmConn(INetConn):
         self.event_closed.set()
         self.swarm.remove_conn(self)
 
-        await self.conn.close()
+        await self.muxed_conn.close()
 
         # This is just for cleaning up state. The connection has already been closed.
         # We *could* optimize this but it really isn't worth it.
@@ -56,7 +56,7 @@ class SwarmConn(INetConn):
     async def _handle_new_streams(self) -> None:
         while True:
             try:
-                stream = await self.conn.accept_stream()
+                stream = await self.muxed_conn.accept_stream()
             except MuxedConnUnavailable:
                 # If there is anything wrong in the MuxedConn,
                 # we should break the loop and close the connection.
@@ -96,7 +96,7 @@ class SwarmConn(INetConn):
         self._tasks.append(asyncio.ensure_future(coro))
 
     async def new_stream(self) -> NetStream:
-        muxed_stream = await self.conn.open_stream()
+        muxed_stream = await self.muxed_conn.open_stream()
         return self._add_stream(muxed_stream)
 
     async def get_streams(self) -> Tuple[NetStream, ...]:
diff --git a/libp2p/network/stream/net_stream.py b/libp2p/network/stream/net_stream.py
index 625a288..0142721 100644
--- a/libp2p/network/stream/net_stream.py
+++ b/libp2p/network/stream/net_stream.py
@@ -1,3 +1,5 @@
+from typing import Optional
+
 from libp2p.stream_muxer.abc import IMuxedStream
 from libp2p.stream_muxer.exceptions import (
     MuxedStreamClosed,
@@ -16,7 +18,7 @@ from .net_stream_interface import INetStream
 class NetStream(INetStream):
 
     muxed_stream: IMuxedStream
-    protocol_id: TProtocol
+    protocol_id: Optional[TProtocol]
 
     def __init__(self, muxed_stream: IMuxedStream) -> None:
         self.muxed_stream = muxed_stream
diff --git a/libp2p/network/swarm.py b/libp2p/network/swarm.py
index bed204e..9d507fb 100644
--- a/libp2p/network/swarm.py
+++ b/libp2p/network/swarm.py
@@ -279,7 +279,7 @@ class Swarm(INetwork):
         """
         Simply remove the connection from Swarm's records, without closing the connection.
         """
-        peer_id = swarm_conn.conn.peer_id
+        peer_id = swarm_conn.muxed_conn.peer_id
         if peer_id not in self.connections:
             return
         # TODO: Should be changed to remove the exact connection,
diff --git a/libp2p/pubsub/pubsub_notifee.py b/libp2p/pubsub/pubsub_notifee.py
index 627152e..85c0bd8 100644
--- a/libp2p/pubsub/pubsub_notifee.py
+++ b/libp2p/pubsub/pubsub_notifee.py
@@ -36,7 +36,7 @@ class PubsubNotifee(INotifee):
         :param network: network the connection was opened on
         :param conn: connection that was opened
         """
-        await self.initiator_peers_queue.put(conn.conn.peer_id)
+        await self.initiator_peers_queue.put(conn.muxed_conn.peer_id)
 
     async def disconnected(self, network: INetwork, conn: INetConn) -> None:
         pass
diff --git a/tests/factories.py b/tests/factories.py
index cecc656..b4e8be2 100644
--- a/tests/factories.py
+++ b/tests/factories.py
@@ -155,7 +155,7 @@ async def mplex_conn_pair_factory(is_secure: bool) -> Tuple[Mplex, Swarm, Mplex,
     conn_0, swarm_0, conn_1, swarm_1 = await swarm_conn_pair_factory(
         is_secure, muxer_opt=muxer_opt
     )
-    return conn_0.conn, swarm_0, conn_1.conn, swarm_1
+    return conn_0.muxed_conn, swarm_0, conn_1.muxed_conn, swarm_1
 
 
 async def mplex_stream_pair_factory(
diff --git a/tests/security/test_security_multistream.py b/tests/security/test_security_multistream.py
index 26d3140..a9fe031 100644
--- a/tests/security/test_security_multistream.py
+++ b/tests/security/test_security_multistream.py
@@ -53,8 +53,8 @@ async def perform_simple_test(
     node2_conn = node2.get_network().connections[peer_id_for_node(node1)]
 
     # Perform assertion
-    assertion_func(node1_conn.conn.secured_conn)
-    assertion_func(node2_conn.conn.secured_conn)
+    assertion_func(node1_conn.muxed_conn.secured_conn)
+    assertion_func(node2_conn.muxed_conn.secured_conn)
 
     # Success, terminate pending tasks.