diff --git a/05-onchain.md b/05-onchain.md
index d1d6a757c..342199b33 100644
--- a/05-onchain.md
+++ b/05-onchain.md
@@ -305,16 +305,19 @@ There are several possible cases for an offered HTLC:
HTLC. In this case, the recipient must use the preimage, once it receives it
from the outgoing HTLC; otherwise, it will lose funds by sending an outgoing
payment without redeeming the incoming payment.
+4. The HTLC is forwarded as above, but the recipient also happens to be the
+ final destination for the payment. In this case, it knows the preimage but
+ as it has not received the full payment, it must not reveal
+ it.[Preimage-Extraction](https://lists.linuxfoundation.org/pipermail/lightning-dev/2020-October/002857.html).
+ This problem is most easily solved by only accepting preimages from
+ responses to corresponding outgoing HTLCs.
### Requirements
A local node:
- - if it receives (or already possesses) a payment preimage for an unresolved
- HTLC output that it has been offered AND for which it has committed to an
- outgoing HTLC:
+ - if it has been offered an unresolved HTLC, AND it has offered a corresponding outgoing HTLC, for which it receives or has already received a payment preimage (by seeing it resolved via an onchain HTLC-success transaction, or via `update_fulfill_htlc`):
- MUST *resolve* the output by spending it, using the HTLC-success
transaction.
- - MUST NOT reveal its own preimage when it's not the final recipient.[Preimage-Extraction](https://lists.linuxfoundation.org/pipermail/lightning-dev/2020-October/002857.html)
- MUST resolve the output of that HTLC-success transaction.
- otherwise:
- if the *remote node* is NOT irrevocably committed to the HTLC: