diff --git a/lib/pleroma/web/activity_pub/mrf/ensure_re_prepended.ex b/lib/pleroma/web/activity_pub/mrf/ensure_re_prepended.ex
index 2627a0007..3bf70b894 100644
--- a/lib/pleroma/web/activity_pub/mrf/ensure_re_prepended.ex
+++ b/lib/pleroma/web/activity_pub/mrf/ensure_re_prepended.ex
@@ -27,7 +27,8 @@ defmodule Pleroma.Web.ActivityPub.MRF.EnsureRePrepended do
 
   def filter_by_summary(_in_reply_to, child), do: child
 
-  def filter(%{"type" => "Create", "object" => child_object} = object) do
+  def filter(%{"type" => "Create", "object" => child_object} = object)
+      when is_map(child_object) do
     child =
       child_object["inReplyTo"]
       |> Object.normalize(child_object["inReplyTo"])
diff --git a/test/web/activity_pub/mrf/ensure_re_prepended_test.exs b/test/web/activity_pub/mrf/ensure_re_prepended_test.exs
index 38ddec5bb..9a283f27d 100644
--- a/test/web/activity_pub/mrf/ensure_re_prepended_test.exs
+++ b/test/web/activity_pub/mrf/ensure_re_prepended_test.exs
@@ -78,5 +78,15 @@ defmodule Pleroma.Web.ActivityPub.MRF.EnsureRePrependedTest do
       assert {:ok, res} = EnsureRePrepended.filter(message)
       assert res == message
     end
+
+    test "it skips if the object is only a reference" do
+      message = %{
+        "type" => "Create",
+        "object" => "somereference"
+      }
+
+      assert {:ok, res} = EnsureRePrepended.filter(message)
+      assert res == message
+    end
   end
 end