diff --git a/lib/pleroma/upload.ex b/lib/pleroma/upload.ex
index 676f232..d9428ab 100644
--- a/lib/pleroma/upload.ex
+++ b/lib/pleroma/upload.ex
@@ -3,8 +3,6 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.Upload do
-  @behaviour Pleroma.Upload
-
   @moduledoc """
   Manage user uploads
 
@@ -38,6 +36,7 @@ defmodule Pleroma.Upload do
   alias Ecto.UUID
   alias Pleroma.Config
   alias Pleroma.Maps
+  alias Pleroma.Web.ActivityPub.Utils
   require Logger
 
   @type source ::
@@ -90,6 +89,7 @@ defmodule Pleroma.Upload do
          {:ok, url_spec} <- Pleroma.Uploaders.Uploader.put_file(opts.uploader, upload) do
       {:ok,
        %{
+         "id" => Utils.generate_object_id(),
          "type" => opts.activity_type,
          "mediaType" => upload.content_type,
          "url" => [