diff --git a/lib/pleroma/web/activity_pub/object_validators/common_fixes.ex b/lib/pleroma/web/activity_pub/object_validators/common_fixes.ex
index a9dc4a312..52afc827e 100644
--- a/lib/pleroma/web/activity_pub/object_validators/common_fixes.ex
+++ b/lib/pleroma/web/activity_pub/object_validators/common_fixes.ex
@@ -4,6 +4,7 @@
 
 defmodule Pleroma.Web.ActivityPub.ObjectValidators.CommonFixes do
   alias Pleroma.EctoType.ActivityPub.ObjectValidators
+  alias Pleroma.Language.LanguageDetector
   alias Pleroma.Maps
   alias Pleroma.Object
   alias Pleroma.Object.Containment
@@ -145,7 +146,8 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.CommonFixes do
     language =
       [
         get_language_from_context(object),
-        get_language_from_content_map(object)
+        get_language_from_content_map(object),
+        get_language_from_content(object)
       ]
       |> Enum.find(&good_locale_code?(&1))
 
@@ -180,6 +182,12 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.CommonFixes do
 
   defp get_language_from_content_map(_), do: nil
 
+  defp get_language_from_content(%{"summary" => summary, "content" => content}) do
+    LanguageDetector.detect("#{summary} #{content}")
+  end
+
+  defp get_language_from_content(_), do: nil
+
   def maybe_add_content_map(%{"language" => language, "content" => content} = object)
       when not_empty_string(language) do
     Map.put(object, "contentMap", Map.put(%{}, language, content))
diff --git a/test/support/language_detector_mock.ex b/test/support/language_detector_mock.ex
index 2a85dcd63..3e6a258ae 100644
--- a/test/support/language_detector_mock.ex
+++ b/test/support/language_detector_mock.ex
@@ -14,5 +14,5 @@ defmodule LanguageDetectorMock do
   def configured?, do: true
 
   @impl Provider
-  def detect(text), do: "fr"
+  def detect(_text), do: "fr"
 end