diff --git a/p2p/types.go b/p2p/types.go
index e76388ff4..b1e5266c6 100644
--- a/p2p/types.go
+++ b/p2p/types.go
@@ -8,9 +8,9 @@ import (
 type ChannelDescriptor = conn.ChannelDescriptor
 type ConnectionStatus = conn.ConnectionStatus
 
+// Envelope contains a message with sender routing info.
 type Envelope struct {
-	// Src is set when the message was sent by a remote peer.
-	Src       Peer
+	Src       Peer          // sender (empty if outbound)
+	Message   proto.Message // message payload
 	ChannelID byte
-	Message   proto.Message
 }