diff --git a/util/src/main/java/org/bouncycastle/asn1/cryptlib/CryptlibObjectIdentifiers.java b/util/src/main/java/org/bouncycastle/asn1/cryptlib/CryptlibObjectIdentifiers.java
index 88dd03f5c1..febe07e19b 100644
--- a/util/src/main/java/org/bouncycastle/asn1/cryptlib/CryptlibObjectIdentifiers.java
+++ b/util/src/main/java/org/bouncycastle/asn1/cryptlib/CryptlibObjectIdentifiers.java
@@ -8,5 +8,10 @@ public class CryptlibObjectIdentifiers
 
     public static final ASN1ObjectIdentifier ecc = cryptlib.branch("1").branch("5");
 
+    /**
+     * Curve25519Legacy for use with ECDH.
+     * @see <a href="https://www.rfc-editor.org/rfc/rfc9580.html#ec-curves">
+     *     RFC9580 - ECC Curves for OpenPGP</a>
+     */
     public static final ASN1ObjectIdentifier curvey25519 = ecc.branch("1");
 }
diff --git a/util/src/main/java/org/bouncycastle/asn1/gnu/GNUObjectIdentifiers.java b/util/src/main/java/org/bouncycastle/asn1/gnu/GNUObjectIdentifiers.java
index 0f82da0b00..e80cab700b 100644
--- a/util/src/main/java/org/bouncycastle/asn1/gnu/GNUObjectIdentifiers.java
+++ b/util/src/main/java/org/bouncycastle/asn1/gnu/GNUObjectIdentifiers.java
@@ -107,5 +107,11 @@ public interface GNUObjectIdentifiers
      */
     ASN1ObjectIdentifier ellipticCurve = new ASN1ObjectIdentifier("1.3.6.1.4.1.11591.15");
 
+    /**
+     * Ed25519Legacy for use with EdDSALegacy.
+     *
+     * @see <a href="https://www.rfc-editor.org/rfc/rfc9580.html#ec-curves">
+     *     RFC9580 - ECC Curves for OpenPGP</a>
+     */
     ASN1ObjectIdentifier Ed25519 = ellipticCurve.branch("1");
 }