diff --git a/lightning/src/offers/signer.rs b/lightning/src/offers/signer.rs
index 6cf6d499adb..a9aac349433 100644
--- a/lightning/src/offers/signer.rs
+++ b/lightning/src/offers/signer.rs
@@ -40,7 +40,7 @@ const WITH_ENCRYPTED_PAYMENT_ID_HMAC_INPUT: &[u8; 16] = &[4; 16];
 const OFFER_PAYMENT_ID_HMAC_INPUT: &[u8; 16] = &[5; 16];
 // HMAC input for a `PaymentId`. The HMAC is used in `AsyncPaymentsContext::OutboundPayment`.
 #[cfg(async_payments)]
-const ASYNC_PAYMENT_ID_HMAC_INPUT: &[u8; 16] = &[5; 16];
+const ASYNC_PAYMENT_ID_HMAC_INPUT: &[u8; 16] = &[6; 16];
 
 /// Message metadata which possibly is derived from [`MetadataMaterial`] such that it can be
 /// verified.