diff --git a/source/new.rst b/source/new.rst
index f1e5163..9a21d2c 100644
--- a/source/new.rst
+++ b/source/new.rst
@@ -261,8 +261,12 @@ Alice and Bob.
    b) Otherwise Bob's device sends back
       a 'vc-request-with-auth' encrypted message
       whose encrypted part contains
-      Bob's own key fingerprint ``Bob_FP``
-      and the second challenge ``AUTH`` from step 1.
+      Bob's own key fingerprint ``Bob_FP``,
+      the second challenge ``AUTH`` from step 1 and
+      optionally an Autocrypt-Gossip header for Alice's
+      Autocrypt key if Bob also sends a copy of message
+      to himself. The latter is needed if Bob has
+      multiple devices.
 
 5. Alice decrypts Bob's 'vc-request-with-auth' message