diff --git a/book/source/openpgp.md b/book/source/openpgp.md
index c76b78e..d50e223 100644
--- a/book/source/openpgp.md
+++ b/book/source/openpgp.md
@@ -57,7 +57,7 @@ In 2007, the IETF published [RFC 4880](https://datatracker.ietf.org/doc/html/rfc
 
 An extension for Elliptic Curve Cryptography was defined in [RFC 6637](https://www.rfc-editor.org/rfc/rfc6637), specifying the use of three NIST prime field curves.
 
-Some implementations explored other non-standardized extensions. Notably, algorithms based on Curve 25519 were tentatively defined in the [rfc4880bis](https://www.ietf.org/archive/id/draft-ietf-openpgp-rfc4880bis-10.html#name-elliptic-curve-cryptography) document. These algorithms are widely used, even though rfc4880bis has never been finalized as a new version of the standard.
+Some implementations explored other non-standardized extensions. Notably, algorithms based on Curve 25519 were tentatively defined in [draft-koch-eddsa-for-openpgp](https://datatracker.ietf.org/doc/draft-koch-eddsa-for-openpgp/) document. These algorithms are widely used, even though `draft-koch-eddsa-for-openpgp` was never formally standardized.
 
 (major-implementations)=
 ### Major implementations of OpenPGP