diff --git a/synapse/groups/groups_server.py b/synapse/groups/groups_server.py
index 23beb3187e..96f112b580 100644
--- a/synapse/groups/groups_server.py
+++ b/synapse/groups/groups_server.py
@@ -609,6 +609,8 @@ class GroupsServerHandler(object):
             raise SynapseError(403, "User not invited to group")
 
         if not self.hs.is_mine_id(user_id):
+            local_attestation = self.attestations.create_attestation(group_id, user_id)
+
             remote_attestation = content["attestation"]
 
             yield self.attestations.verify_attestation(
@@ -617,10 +619,9 @@ class GroupsServerHandler(object):
                 group_id=group_id,
             )
         else:
+            local_attestation = None
             remote_attestation = None
 
-        local_attestation = self.attestations.create_attestation(group_id, user_id)
-
         is_public = _parse_visibility_from_contents(content)
 
         yield self.store.add_user_to_group(