diff --git a/libp2p/stream_muxer/mplex/mplex_stream.py b/libp2p/stream_muxer/mplex/mplex_stream.py
index 8f45495f..a7a510b6 100644
--- a/libp2p/stream_muxer/mplex/mplex_stream.py
+++ b/libp2p/stream_muxer/mplex/mplex_stream.py
@@ -31,6 +31,7 @@ if TYPE_CHECKING:
         Mplex,
     )
 
+
 class ReadWriteLock:
     def __init__(self):
         self._readers = 0
@@ -55,6 +56,7 @@ class ReadWriteLock:
     def release_write(self):
         self._write_lock.release()
 
+
 class MplexStream(IMuxedStream):
     """
     reference: https://github.com/libp2p/go-mplex/blob/master/stream.go