diff --git a/pkg/media/validate.go b/pkg/media/validate.go
index 5a404c9e3..223b86df5 100644
--- a/pkg/media/validate.go
+++ b/pkg/media/validate.go
@@ -174,12 +174,13 @@ func (mm *MediaManager) ValidateMP4(ctx context.Context, input io.Reader, local
 		DeleteAfter:        deleteAfter,
 		Published:          meta.Published,
 	}
-	// The bytes archived above are the bare canonical .m4s, but the live
-	// distribution pipelines (HLS transmux, WebRTC, transcode, thumbnail) and
-	// the replication forwarders still consume a presentation MP4. Synthesize
-	// a flat MP4 over the canonical segments for the notification; the segment
-	// bytes (and their signatures) pass through verbatim in the mdat envelope,
-	// so a receiving node re-validates it unchanged.
+	// The bytes archived above are the bare canonical .m4s. The local
+	// distribution pipelines (HLS transmux, WebRTC, transcode, thumbnail) still
+	// consume a presentation MP4, so synthesize a flat MP4 over the canonical
+	// segments for the notification's Data field; the segment bytes (and their
+	// signatures) pass through verbatim in the mdat envelope. Replication
+	// forwarders instead ship the bare canonical Muxl bytes (see the iroh and
+	// websocket senders), which a receiving node re-validates unchanged.
 	var playable bytes.Buffer
 	if err := muxl.RunMuxlWrap(ctx, bytes.NewReader(buf), "flat", &playable); err != nil {
 		return fmt.Errorf("wrap segment for distribution: %w", err)
diff --git a/pkg/replication/iroh_replicator/kv.go b/pkg/replication/iroh_replicator/kv.go
index 15ca1b9a0..8ef853c7a 100644
--- a/pkg/replication/iroh_replicator/kv.go
+++ b/pkg/replication/iroh_replicator/kv.go
@@ -445,7 +445,10 @@ func (swarm *IrohSwarm) SendSegment(ctx context.Context, not *media.NewSegmentNo
 	go func() {
 		spmetrics.SendSegmentCalls.Inc()
 		defer spmetrics.SendSegmentCalls.Dec()
-		err = swarm.Node.SendSegment(not.Segment.RepoDID, not.Data)
+		// Ship the bare canonical MUXL segment (blindly concatenatable, no
+		// presentation header) — smaller than the flat MP4 and the canonical
+		// form. The receiving node re-validates it verbatim via ValidateMP4.
+		err = swarm.Node.SendSegment(not.Segment.RepoDID, not.Muxl)
 		if err != nil {
 			log.Error(ctx, "could not send segment to swarm", "error", err)
 		}
diff --git a/pkg/spxrpc/place_stream_live.go b/pkg/spxrpc/place_stream_live.go
index 8c703052a..27f50b49a 100644
--- a/pkg/spxrpc/place_stream_live.go
+++ b/pkg/spxrpc/place_stream_live.go
@@ -239,7 +239,9 @@ func (s *Server) handlePlaceStreamLiveSubscribeSegments(c echo.Context) error {
 					continue
 				}
 				log.Debug(ctx, "got segment", "file", file.Filepath)
-				err := ws.WriteMessage(websocket.BinaryMessage, file.Data)
+				// Ship the bare canonical MUXL segment; the receiver
+				// re-validates it via ValidateMP4 (which accepts bare .m4s).
+				err := ws.WriteMessage(websocket.BinaryMessage, file.Muxl)
 				if err != nil {
 					log.Error(ctx, "could not write message", "error", err)
 					cancel()