diff --git a/lightning/src/offers/parse.rs b/lightning/src/offers/parse.rs
index 6aaa24a6f78..3be98108cbc 100644
--- a/lightning/src/offers/parse.rs
+++ b/lightning/src/offers/parse.rs
@@ -147,6 +147,9 @@ pub enum Bolt12SemanticError {
 	/// An amount was expected but was missing.
 	MissingAmount,
 	/// The amount exceeded the total bitcoin supply.
+	///
+	/// This error can also occur if the amount in an invoice does not match the expected
+	/// amount specified in the associated `InvoiceRequest` or `Refund`.
 	InvalidAmount,
 	/// An amount was provided but was not sufficient in value.
 	InsufficientAmount,