diff --git a/libp2p/stream_muxer/mplex/mplex.py b/libp2p/stream_muxer/mplex/mplex.py
index e75d8eea..233a9e66 100644
--- a/libp2p/stream_muxer/mplex/mplex.py
+++ b/libp2p/stream_muxer/mplex/mplex.py
@@ -42,7 +42,7 @@ class Mplex(IMuxedConn):
         for new muxed streams
         :param peer_id: peer_id of peer the connection is to
         """
-        super(Mplex, self).__init__(secured_conn, generic_protocol_handler, peer_id)
+        super().__init__(secured_conn, generic_protocol_handler, peer_id)
 
         self.secured_conn = secured_conn
         self.raw_conn = secured_conn.get_conn()
@@ -111,7 +111,6 @@ class Mplex(IMuxedConn):
     async def accept_stream(self) -> None:
         """
         accepts a muxed stream opened by the other end
-        :return: the accepted stream
         """
         stream_id = await self.stream_queue.get()
         stream = MplexStream(stream_id, False, self)
diff --git a/libp2p/stream_muxer/muxed_connection_interface.py b/libp2p/stream_muxer/muxed_connection_interface.py
index b7bd4e6b..9236fbca 100644
--- a/libp2p/stream_muxer/muxed_connection_interface.py
+++ b/libp2p/stream_muxer/muxed_connection_interface.py
@@ -1,6 +1,13 @@
 from abc import ABC, abstractmethod
 
-from libp2p.peer.id import ID
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from multiaddr import Multiaddr
+    from libp2p.security.secure_conn_interface import ISecureConn
+    from libp2p.network.swarm import GenericProtocolHandlerFn
+    from libp2p.peer.id import ID
+    from libp2p.stream_muxer.muxed_stream_interface import IMuxedStream
 
 
 class IMuxedConn(ABC):
@@ -9,10 +16,15 @@ class IMuxedConn(ABC):
     """
 
     initiator: bool
-    peer_id: ID
+    peer_id: "ID"
 
     @abstractmethod
-    def __init__(self, conn, generic_protocol_handler, peer_id):
+    def __init__(
+        self,
+        conn: "ISecureConn",
+        generic_protocol_handler: "GenericProtocolHandlerFn",
+        peer_id: "ID",
+    ) -> None:
         """
         create a new muxed connection
         :param conn: an instance of secured connection
@@ -22,21 +34,22 @@ class IMuxedConn(ABC):
         """
 
     @abstractmethod
-    def close(self):
+    def close(self) -> None:
         """
         close connection
-        :return: true if successful
         """
 
     @abstractmethod
-    def is_closed(self):
+    def is_closed(self) -> bool:
         """
         check connection is fully closed
         :return: true if successful
         """
 
     @abstractmethod
-    def open_stream(self, protocol_id, multi_addr):
+    async def open_stream(
+        self, protocol_id: str, multi_addr: "Multiaddr"
+    ) -> "IMuxedStream":
         """
         creates a new muxed_stream
         :param protocol_id: protocol_id of stream
@@ -45,8 +58,7 @@ class IMuxedConn(ABC):
         """
 
     @abstractmethod
-    def accept_stream(self):
+    async def accept_stream(self) -> None:
         """
         accepts a muxed stream opened by the other end
-        :return: the accepted stream
         """