diff --git a/ChangeLog b/ChangeLog
index b7624be50428a2eacea0df829504c75b1da3d94d..b5db3abbb43596878af9eaa98ffa7c59194e5647 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2020-01-02  Niels Möller  <nisse@lysator.liu.se>
+
+	* eddsa-internal.h (struct ecc_eddsa): Add magic "dom" string,
+	needed for ed448.
+
 2020-01-01  Niels Möller  <nisse@lysator.liu.se>
 
 	* ecc-448.c (ecc_mod_pow_2kp1): New function.
diff --git a/ed25519-sha512.c b/ed25519-sha512.c
index c1dd683141e320e647a1e411df42aa7efcba0220..09d0f8a5900cb215e2963a00c3914c54168f7f78 100644
--- a/ed25519-sha512.c
+++ b/ed25519-sha512.c
@@ -42,6 +42,7 @@ const struct ecc_eddsa _nettle_ed25519_sha512 =
   {
     (nettle_hash_update_func *) sha512_update,
     (nettle_hash_digest_func *) sha512_digest,
+    NULL, 0,
     ~(mp_limb_t) 7,
     (mp_limb_t) 1 << (254 % GMP_NUMB_BITS),
   };
diff --git a/eddsa-internal.h b/eddsa-internal.h
index 9c0a1eca8fc71a8e9d6ca4faa87b731872154f33..4dd441f0c8568f3738d326cf17b18858d46c6fec 100644
--- a/eddsa-internal.h
+++ b/eddsa-internal.h
@@ -58,6 +58,8 @@ struct ecc_eddsa
   /* Hash function to use */
   nettle_hash_update_func *update;
   nettle_hash_digest_func *digest;
+  const uint8_t *dom;
+  unsigned dom_size;
   /* For generating the secret scalar */
   mp_limb_t low_mask;
   mp_limb_t high_bit;