diff --git a/h/presenters/mention_json.py b/h/presenters/mention_json.py
index 492a9efa602..3aa48e0be93 100644
--- a/h/presenters/mention_json.py
+++ b/h/presenters/mention_json.py
@@ -3,6 +3,7 @@
 from pyramid.request import Request
 
 from h.models import Mention
+from h.util.datetime import utc_iso8601
 from h.util.user import format_userid, get_user_url
 
 
@@ -22,4 +23,6 @@ def asdict(self) -> dict[str, Any]:
             "username": self._mention.user.username,
             "display_name": self._mention.user.display_name,
             "link": get_user_url(self._mention.user, self._request),
+            "description": self._mention.user.description,
+            "activation_date": utc_iso8601(self._mention.user.activation_date),
         }
diff --git a/tests/unit/h/presenters/mention_json_test.py b/tests/unit/h/presenters/mention_json_test.py
index 8857c2f7ceb..96e5f74b403 100644
--- a/tests/unit/h/presenters/mention_json_test.py
+++ b/tests/unit/h/presenters/mention_json_test.py
@@ -2,6 +2,7 @@
 
 from h.models import Mention
 from h.presenters.mention_json import MentionJSONPresenter
+from h.util.datetime import utc_iso8601
 from h.util.user import format_userid
 
 
@@ -17,6 +18,8 @@ def test_as_dict(self, user, annotation, pyramid_request):
             "username": user.username,
             "display_name": user.display_name,
             "link": f"http://example.com/users/{user.username}",
+            "description": user.description,
+            "activation_date": utc_iso8601(user.activation_date),
         }
 
     def test_as_dict_with_different_username(self, user, annotation, pyramid_request):