diff --git a/bookwyrm/activitypub/base_activity.py b/bookwyrm/activitypub/base_activity.py
index 0672fbb8..620579a0 100644
--- a/bookwyrm/activitypub/base_activity.py
+++ b/bookwyrm/activitypub/base_activity.py
@@ -124,7 +124,7 @@ class ActivityObject:
                         formatted_value = timezone.make_aware(date_value)
                     except ValueError:
                         formatted_value = date_value
-                except ParserError:
+                except (ParserError, TypeError):
                     formatted_value = None
             elif isinstance(model_field, ForwardManyToOneDescriptor) and \
                     formatted_value:
@@ -182,12 +182,17 @@ class ActivityObject:
                 model = model_field.model
                 items = []
                 for link in values:
-                    # check that the Type matches the model (because Status
-                    # tags contain both user mentions and book tags)
-                    if not model.activity_serializer.type == link.get('type'):
-                        continue
+                    if isinstance(link, dict):
+                        # check that the Type matches the model (Status
+                        # tags contain both user mentions and book tags)
+                        if not model.activity_serializer.type == \
+                                link.get('type'):
+                            continue
+                        remote_id = link.get('href')
+                    else:
+                        remote_id = link
                     items.append(
-                        resolve_remote_id(model, link.get('href'))
+                        resolve_remote_id(model, remote_id)
                     )
                 getattr(instance, model_key).set(items)
 
diff --git a/bookwyrm/models/base_model.py b/bookwyrm/models/base_model.py
index 29301fb5..877f094e 100644
--- a/bookwyrm/models/base_model.py
+++ b/bookwyrm/models/base_model.py
@@ -10,7 +10,9 @@ from Crypto.PublicKey import RSA
 from Crypto.Signature import pkcs1_15
 from Crypto.Hash import SHA256
 from django.db import models
-from django.db.models.fields.files import ImageFieldFile
+from django.db.models.fields.files import ImageFileDescriptor
+from django.db.models.fields.related_descriptors \
+        import ManyToManyDescriptor
 from django.dispatch import receiver
 
 from bookwyrm import activitypub
@@ -72,13 +74,16 @@ class ActivitypubMixin:
                 # this field on the model isn't serialized
                 continue
             value = getattr(self, mapping.model_key)
+            model_field_type = getattr(self.__class__, mapping.model_key)
             if hasattr(value, 'remote_id'):
                 # this is probably a foreign key field, which we want to
                 # serialize as just the remote_id url reference
                 value = value.remote_id
+            elif isinstance(model_field_type, ManyToManyDescriptor):
+                value = [i.remote_id for i in value.all()]
             elif isinstance(value, datetime):
                 value = value.isoformat()
-            elif isinstance(value, ImageFieldFile):
+            elif isinstance(model_field_type, ImageFileDescriptor):
                 value = image_formatter(value)
 
             # run the custom formatter function set in the model
diff --git a/bookwyrm/models/book.py b/bookwyrm/models/book.py
index 8892119a..70eb8652 100644
--- a/bookwyrm/models/book.py
+++ b/bookwyrm/models/book.py
@@ -55,15 +55,10 @@ class Book(ActivitypubMixin, BookWyrmModel):
     published_date = models.DateTimeField(blank=True, null=True)
     objects = InheritanceManager()
 
-    @property
-    def ap_authors(self):
-        ''' the activitypub serialization should be a list of author ids '''
-        return [a.remote_id for a in self.authors.all()]
-
     activity_mappings = [
         ActivityMapping('id', 'remote_id'),
 
-        ActivityMapping('authors', 'ap_authors'),
+        ActivityMapping('authors', 'authors'),
         ActivityMapping('firstPublishedDate', 'firstpublished_date'),
         ActivityMapping('publishedDate', 'published_date'),
 
@@ -91,7 +86,7 @@ class Book(ActivitypubMixin, BookWyrmModel):
         ActivityMapping('publishers', 'publishers'),
 
         ActivityMapping('lccn', 'lccn'),
-        ActivityMapping('editions', 'editions_path'),
+        ActivityMapping('editions', 'editions'),
         ActivityMapping('cover', 'cover'),
     ]
 
@@ -127,16 +122,6 @@ class Work(OrderedCollectionPageMixin, Book):
         null=True
     )
 
-    @property
-    def editions_path(self):
-        ''' it'd be nice to serialize the edition instead but, recursion '''
-        default = self.default_edition
-        ed_list = [
-            e.remote_id for e in \
-                    self.edition_set.filter(~Q(id=default.id)).all()
-        ]
-        return [default.remote_id] + ed_list
-
 
     def to_edition_list(self, **kwargs):
         ''' activitypub serialization for this work's editions '''