diff --git a/lib/pleroma/constants.ex b/lib/pleroma/constants.ex
index 2d08cd7a1..42751940a 100644
--- a/lib/pleroma/constants.ex
+++ b/lib/pleroma/constants.ex
@@ -37,6 +37,7 @@ defmodule Pleroma.Constants do
       "updated",
       "emoji",
       "content",
+      "contentMap",
       "summary",
       "sensitive",
       "attachment",
diff --git a/lib/pleroma/web/activity_pub/transmogrifier.ex b/lib/pleroma/web/activity_pub/transmogrifier.ex
index a6f711733..1cea12aa3 100644
--- a/lib/pleroma/web/activity_pub/transmogrifier.ex
+++ b/lib/pleroma/web/activity_pub/transmogrifier.ex
@@ -6,6 +6,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
   @moduledoc """
   A module to handle coding from internal to wire ActivityPub and back.
   """
+  alias Pleroma.Web.ActivityPub.ObjectValidators.CommonFixes
   alias Pleroma.Activity
   alias Pleroma.EctoType.ActivityPub.ObjectValidators
   alias Pleroma.Maps
@@ -167,7 +168,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
 
   def fix_quote_url_and_maybe_fetch(object, options \\ []) do
     quote_url =
-      case Pleroma.Web.ActivityPub.ObjectValidators.CommonFixes.fix_quote_url(object) do
+      case CommonFixes.fix_quote_url(object) do
         %{"quoteUrl" => quote_url} -> quote_url
         _ -> nil
       end
@@ -720,6 +721,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     |> set_reply_to_uri
     |> set_quote_url
     |> set_replies
+    |> CommonFixes.maybe_add_content_map()
     |> strip_internal_fields
     |> strip_internal_tags
     |> set_type
diff --git a/test/pleroma/web/activity_pub/transmogrifier_test.exs b/test/pleroma/web/activity_pub/transmogrifier_test.exs
index ebf70b3e6..a25c6fe1b 100644
--- a/test/pleroma/web/activity_pub/transmogrifier_test.exs
+++ b/test/pleroma/web/activity_pub/transmogrifier_test.exs
@@ -639,5 +639,14 @@ defmodule Pleroma.Web.ActivityPub.TransmogrifierTest do
       processed = Transmogrifier.prepare_object(original)
       assert processed["formerRepresentations"] == original["formerRepresentations"]
     end
+
+    test "it uses contentMap to specify post language" do
+      user = insert(:user)
+
+      {:ok, activity} = CommonAPI.post(user, %{status: "Cześć", language: "pl"})
+      {:ok, modified} = Transmogrifier.prepare_object(activity.object.data)
+
+      assert %{"contentMap" => %{"pl" => "Cześć"}} = modified["object"]
+    end
   end
 end