diff --git a/lightning/src/onion_message/messenger.rs b/lightning/src/onion_message/messenger.rs
index f735f04f620..a33ee4f27b7 100644
--- a/lightning/src/onion_message/messenger.rs
+++ b/lightning/src/onion_message/messenger.rs
@@ -424,6 +424,7 @@ pub enum MessageSendInstructions {
 	},
 	/// Indicates that a message is being sent as a reply to a received message.
 	ForReply {
+		/// The instructions provided by the [`Responder`].
 		instructions: ResponseInstruction,
 	},
 }