diff --git a/bookwyrm/activitypub/base_activity.py b/bookwyrm/activitypub/base_activity.py
index 15ca5a93..6bee25f6 100644
--- a/bookwyrm/activitypub/base_activity.py
+++ b/bookwyrm/activitypub/base_activity.py
@@ -227,7 +227,7 @@ def set_related_field(
     model_field = getattr(model, related_field_name)
     if hasattr(model_field, "activitypub_field"):
         setattr(activity, getattr(model_field, "activitypub_field"), instance.remote_id)
-    item = activity.to_model()
+    item = activity.to_model(model=model)
 
     # if the related field isn't serialized (attachments on Status), then
     # we have to set it post-creation
@@ -298,6 +298,7 @@ class Link(ActivityObject):
     mediaType: str = None
     id: str = None
     attributedTo: str = None
+    availability: str = None
     type: str = "Link"
 
     def serialize(self, **kwargs):
diff --git a/bookwyrm/tests/models/test_book_model.py b/bookwyrm/tests/models/test_book_model.py
index d74fa4ca..d4f59fa5 100644
--- a/bookwyrm/tests/models/test_book_model.py
+++ b/bookwyrm/tests/models/test_book_model.py
@@ -1,7 +1,6 @@
 """ testing models """
 from dateutil.parser import parse
 
-from imagekit.models import ImageSpecField
 from django.test import TestCase
 from django.utils import timezone
 
diff --git a/bookwyrm/tests/views/books/test_links.py b/bookwyrm/tests/views/books/test_links.py
index 2aee5aed..3379786b 100644
--- a/bookwyrm/tests/views/books/test_links.py
+++ b/bookwyrm/tests/views/books/test_links.py
@@ -80,6 +80,15 @@ class LinkViews(TestCase):
         activity = json.loads(mock.call_args[1]["args"][1])
         self.assertEqual(activity["type"], "Update")
         self.assertEqual(activity["object"]["type"], "Edition")
+        self.assertIsInstance(activity["object"]["fileLinks"], list)
+        self.assertEqual(
+            activity["object"]["fileLinks"][0]["href"], "https://www.example.com"
+        )
+        self.assertEqual(activity["object"]["fileLinks"][0]["mediaType"], "HTML")
+        self.assertEqual(
+            activity["object"]["fileLinks"][0]["attributedTo"],
+            self.local_user.remote_id,
+        )
 
         link = models.FileLink.objects.get()
         self.assertEqual(link.name, "www.example.com")
diff --git a/bookwyrm/tests/views/inbox/test_inbox_update.py b/bookwyrm/tests/views/inbox/test_inbox_update.py
index 963742c8..18b2e5d5 100644
--- a/bookwyrm/tests/views/inbox/test_inbox_update.py
+++ b/bookwyrm/tests/views/inbox/test_inbox_update.py
@@ -6,7 +6,6 @@ from unittest.mock import patch
 from django.test import TestCase
 
 from bookwyrm import models, views
-from bookwyrm.activitypub.base_activity import set_related_field
 
 
 # pylint: disable=too-many-public-methods