diff --git a/lib/pleroma/web/pleroma_api/views/chat_view.ex b/lib/pleroma/web/pleroma_api/views/chat_view.ex
index 21f0612ff..08d5110c3 100644
--- a/lib/pleroma/web/pleroma_api/views/chat_view.ex
+++ b/lib/pleroma/web/pleroma_api/views/chat_view.ex
@@ -7,6 +7,7 @@ defmodule Pleroma.Web.PleromaAPI.ChatView do
 
   alias Pleroma.Chat
   alias Pleroma.User
+  alias Pleroma.Web.CommonAPI.Utils
   alias Pleroma.Web.MastodonAPI.AccountView
   alias Pleroma.Web.PleromaAPI.ChatMessageView
 
@@ -20,7 +21,8 @@ def render("show.json", %{chat: %Chat{} = chat} = opts) do
       account: AccountView.render("show.json", Map.put(opts, :user, recipient)),
       unread: chat.unread,
       last_message:
-        last_message && ChatMessageView.render("show.json", chat: chat, object: last_message)
+        last_message && ChatMessageView.render("show.json", chat: chat, object: last_message),
+      updated_at: Utils.to_masto_date(chat.updated_at)
     }
   end
 
diff --git a/test/web/pleroma_api/views/chat_view_test.exs b/test/web/pleroma_api/views/chat_view_test.exs
index e24e29835..6062a0cfe 100644
--- a/test/web/pleroma_api/views/chat_view_test.exs
+++ b/test/web/pleroma_api/views/chat_view_test.exs
@@ -8,6 +8,7 @@ defmodule Pleroma.Web.PleromaAPI.ChatViewTest do
   alias Pleroma.Chat
   alias Pleroma.Object
   alias Pleroma.Web.CommonAPI
+  alias Pleroma.Web.CommonAPI.Utils
   alias Pleroma.Web.MastodonAPI.AccountView
   alias Pleroma.Web.PleromaAPI.ChatMessageView
   alias Pleroma.Web.PleromaAPI.ChatView
@@ -26,7 +27,8 @@ test "it represents a chat" do
              id: "#{chat.id}",
              account: AccountView.render("show.json", user: recipient),
              unread: 0,
-             last_message: nil
+             last_message: nil,
+             updated_at: Utils.to_masto_date(chat.updated_at)
            }
 
     {:ok, chat_message_creation} = CommonAPI.post_chat_message(user, recipient, "hello")