diff --git a/libp2p/stream_muxer/abc.py b/libp2p/stream_muxer/abc.py
index 2c577c7..547e917 100644
--- a/libp2p/stream_muxer/abc.py
+++ b/libp2p/stream_muxer/abc.py
@@ -82,11 +82,10 @@ class IMuxedStream(ReadWriteCloser):
     mplex_conn: IMuxedConn
 
     @abstractmethod
-    async def reset(self) -> bool:
+    async def reset(self) -> None:
         """
         closes both ends of the stream
         tells this remote side to hang up
-        :return: true if successful
         """
 
     @abstractmethod
diff --git a/libp2p/stream_muxer/mplex/mplex.py b/libp2p/stream_muxer/mplex/mplex.py
index af1282e..f342978 100644
--- a/libp2p/stream_muxer/mplex/mplex.py
+++ b/libp2p/stream_muxer/mplex/mplex.py
@@ -173,6 +173,7 @@ class Mplex(IMuxedConn):
                 if flag == HeaderTags.NewStream.value:
                     if is_stream_id_seen:
                         # `NewStream` for the same id is received twice...
+                        # TODO: Shutdown
                         pass
                     await self.accept_stream(stream_id, message.decode())
                 elif flag in (
@@ -187,10 +188,49 @@ class Mplex(IMuxedConn):
                     async with self.streams_lock:
                         stream = self.streams[stream_id]
                     await stream.incoming_data.put(message)
-                # elif flag in (
-                #     HeaderTags.CloseInitiator.value,
-                #     HeaderTags.CloseReceiver.value
-                # ):
+                elif flag in (
+                    HeaderTags.CloseInitiator.value,
+                    HeaderTags.CloseReceiver.value,
+                ):
+                    if not is_stream_id_seen:
+                        continue
+                    stream: MplexStream
+                    async with self.streams_lock:
+                        stream = self.streams[stream_id]
+                    is_local_closed: bool
+                    async with stream.close_lock:
+                        stream.event_remote_closed.set()
+                        is_local_closed = stream.event_local_closed.is_set()
+                    # If local is also closed, both sides are closed. Then, we should clean up
+                    #   this stream.
+                    if is_local_closed:
+                        async with self.streams_lock:
+                            del self.streams[stream_id]
+                elif flag in (
+                    HeaderTags.ResetInitiator.value,
+                    HeaderTags.ResetReceiver.value,
+                ):
+                    if not is_stream_id_seen:
+                        # This is *ok*. We forget the stream on reset.
+                        continue
+                    stream: MplexStream
+                    async with self.streams_lock:
+                        stream = self.streams[stream_id]
+                    async with stream.close_lock:
+                        if not stream.event_remote_closed.is_set():
+                            stream.event_reset.set()
+                            stream.event_remote_closed.set()
+                        if not stream.event_local_closed.is_set():
+                            stream.event_local_closed.close()
+                    async with self.streams_lock:
+                        del self.streams[stream_id]
+                else:
+                    # TODO: logging
+                    print(f"message with unknown header on stream {stream_id}")
+                    if is_stream_id_seen:
+                        async with self.streams_lock:
+                            stream = self.streams[stream_id]
+                            await stream.reset()
 
             # Force context switch
             await asyncio.sleep(0)