diff --git a/libp2p/stream_muxer/mplex/mplex_stream.py b/libp2p/stream_muxer/mplex/mplex_stream.py
index 46e89149..73b6292e 100644
--- a/libp2p/stream_muxer/mplex/mplex_stream.py
+++ b/libp2p/stream_muxer/mplex/mplex_stream.py
@@ -146,7 +146,7 @@ class MplexStream(IMuxedStream):
         :return: number of bytes written
         """
         if self.event_local_closed.is_set():
-            raise MplexStreamClosed(f"cannot write to closed stream: data={data}")
+            raise MplexStreamClosed(f"cannot write to closed stream: data={data!r}")
         flag = (
             HeaderTags.MessageInitiator
             if self.is_initiator
diff --git a/libp2p/utils.py b/libp2p/utils.py
index 677f054c..3d0794a1 100644
--- a/libp2p/utils.py
+++ b/libp2p/utils.py
@@ -75,7 +75,7 @@ async def read_delim(reader: Reader) -> bytes:
         raise ParseError(f"`len(msg_bytes)` should not be 0")
     if msg_bytes[-1:] != b"\n":
         raise ParseError(
-            f'`msg_bytes` is not delimited by b"\\n": `msg_bytes`={msg_bytes}'
+            f'`msg_bytes` is not delimited by b"\\n": `msg_bytes`={msg_bytes!r}'
         )
     return msg_bytes[:-1]