diff --git a/lib/mobilizon/events/events.ex b/lib/mobilizon/events/events.ex
index 7eb44363f..c6c47b72a 100644
--- a/lib/mobilizon/events/events.ex
+++ b/lib/mobilizon/events/events.ex
@@ -592,7 +592,12 @@ defmodule Mobilizon.Events do
   """
   @spec list_participants_for_event(String.t(), list(atom()), integer | nil, integer | nil) ::
           [Participant.t()]
-  def list_participants_for_event(uuid, roles \\ @default_participant_roles, page, limit) do
+  def list_participants_for_event(
+        uuid,
+        roles \\ @default_participant_roles,
+        page \\ nil,
+        limit \\ nil
+      ) do
     uuid
     |> list_participants_for_event_query()
     |> filter_role(roles)
diff --git a/lib/mobilizon_web/resolvers/event.ex b/lib/mobilizon_web/resolvers/event.ex
index b1b14341b..96783f3c2 100644
--- a/lib/mobilizon_web/resolvers/event.ex
+++ b/lib/mobilizon_web/resolvers/event.ex
@@ -201,7 +201,7 @@ defmodule MobilizonWeb.Resolvers.Event do
         }
       ) do
     # Check that moderator provided is rightly authenticated
-    with {:is_owned, true, moderator_actor} <- User.owns_actor(user, moderator_actor_id),
+    with {:is_owned, moderator_actor} <- User.owns_actor(user, moderator_actor_id),
          # Check that participation already exists
          {:has_participation, %Participant{role: :not_approved} = participation} <-
            {:has_participation, Mobilizon.Events.get_participant(participation_id)},
@@ -213,7 +213,7 @@ defmodule MobilizonWeb.Resolvers.Event do
            MobilizonWeb.API.Participations.accept(participation, moderator_actor) do
       {:ok, participation}
     else
-      {:is_owned, false} ->
+      {:is_owned, nil} ->
         {:error, "Moderator Actor ID is not owned by authenticated user"}
 
       {:has_participation, %Participant{role: role, id: id}} ->
@@ -238,7 +238,7 @@ defmodule MobilizonWeb.Resolvers.Event do
         }
       ) do
     # Check that moderator provided is rightly authenticated
-    with {:is_owned, true, moderator_actor} <- User.owns_actor(user, moderator_actor_id),
+    with {:is_owned, moderator_actor} <- User.owns_actor(user, moderator_actor_id),
          # Check that participation really exists
          {:has_participation, %Participant{} = participation} <-
            {:has_participation, Mobilizon.Events.get_participant(participation_id)},
@@ -261,7 +261,7 @@ defmodule MobilizonWeb.Resolvers.Event do
         }
       }
     else
-      {:is_owned, false} ->
+      {:is_owned, nil} ->
         {:error, "Moderator Actor ID is not owned by authenticated user"}
 
       {:actor_approve_permission, _} ->
diff --git a/lib/mobilizon_web/schema/event.ex b/lib/mobilizon_web/schema/event.ex
index 2ccd44405..5584a9d35 100644
--- a/lib/mobilizon_web/schema/event.ex
+++ b/lib/mobilizon_web/schema/event.ex
@@ -225,7 +225,7 @@ defmodule MobilizonWeb.Schema.EventType do
       arg(:begins_on, non_null(:datetime))
       arg(:ends_on, :datetime)
       arg(:status, :event_status)
-      arg(:visibility, :event_visibility, default_value: :private)
+      arg(:visibility, :event_visibility, default_value: :public)
       arg(:join_options, :event_join_options, default_value: :free)
 
       arg(:tags, list_of(:string),
@@ -258,8 +258,8 @@ defmodule MobilizonWeb.Schema.EventType do
       arg(:begins_on, :datetime)
       arg(:ends_on, :datetime)
       arg(:status, :event_status)
-      arg(:visibility, :event_visibility)
-      arg(:join_options, :event_join_options)
+      arg(:visibility, :event_visibility, default_value: :public)
+      arg(:join_options, :event_join_options, default_value: :free)
 
       arg(:tags, list_of(:string), description: "The list of tags associated to the event")
 
diff --git a/lib/service/activity_pub/activity_pub.ex b/lib/service/activity_pub/activity_pub.ex
index 5dab5b12e..604a60165 100644
--- a/lib/service/activity_pub/activity_pub.ex
+++ b/lib/service/activity_pub/activity_pub.ex
@@ -25,7 +25,8 @@ defmodule Mobilizon.Service.ActivityPub do
   alias Mobilizon.Service.ActivityPub.{Activity, Convertible}
 
   require Logger
-  import Mobilizon.Service.ActivityPub.{Utils, Visibility}
+  import Mobilizon.Service.ActivityPub.Utils
+  import Mobilizon.Service.ActivityPub.Visibility
 
   @doc """
   Get recipients for an activity or object
diff --git a/lib/service/activity_pub/converters/event.ex b/lib/service/activity_pub/converters/event.ex
index ae19c2831..bba57d009 100644
--- a/lib/service/activity_pub/converters/event.ex
+++ b/lib/service/activity_pub/converters/event.ex
@@ -186,6 +186,7 @@ defmodule Mobilizon.Service.ActivityPub.Converters.Event do
       "mediaType" => "text/html",
       "startTime" => event.begins_on |> date_to_string(),
       "endTime" => event.ends_on |> date_to_string(),
+      "joinOptions" => to_string(event.join_options),
       "tag" => event.tags |> build_tags(),
       "id" => event.url,
       "url" => event.url
diff --git a/lib/service/activity_pub/transmogrifier.ex b/lib/service/activity_pub/transmogrifier.ex
index ef34e1477..fedd980ee 100644
--- a/lib/service/activity_pub/transmogrifier.ex
+++ b/lib/service/activity_pub/transmogrifier.ex
@@ -315,8 +315,9 @@ defmodule Mobilizon.Service.ActivityPub.Transmogrifier do
         %{"type" => "Update", "object" => %{"type" => "Event"} = object, "actor" => actor} =
           _update
       ) do
-    with {:ok, %{"actor" => existing_organizer_actor_url} = _existing_event_data} <-
+    with {:ok, %{"actor" => existing_organizer_actor_url} = existing_event_data} <-
            fetch_obj_helper_as_activity_streams(object),
+         object <- Map.merge(existing_event_data, object),
          {:ok, %Actor{url: actor_url}} <- actor |> Utils.get_url() |> Actors.get_actor_by_url(),
          true <- Utils.get_url(existing_organizer_actor_url) == actor_url do
       ActivityPub.update(%{