diff --git a/CHANGELOG b/CHANGELOG
index 7cd7714af..b230b1556 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -3,6 +3,16 @@ Changelog
 
 .. towncrier
 
+0.9.1 (2018-04-17)
+------------------
+
+Bugfixes:
+
+- Allow null values for musicbrainz_id in Audio ActivityPub representation
+- Fixed broken permission check on library scanning and too aggressive page
+  validation
+
+
 0.9 (2018-04-17)
 ----------------
 
diff --git a/api/funkwhale_api/__init__.py b/api/funkwhale_api/__init__.py
index 70cf5b1f8..f3a544e46 100644
--- a/api/funkwhale_api/__init__.py
+++ b/api/funkwhale_api/__init__.py
@@ -1,3 +1,3 @@
 # -*- coding: utf-8 -*-
-__version__ = '0.9'
+__version__ = '0.9.1'
 __version_info__ = tuple([int(num) if num.isdigit() else num for num in __version__.replace('-', '.', 1).split('.')])
diff --git a/api/funkwhale_api/federation/permissions.py b/api/funkwhale_api/federation/permissions.py
index 370328eaa..c6f0660b1 100644
--- a/api/funkwhale_api/federation/permissions.py
+++ b/api/funkwhale_api/federation/permissions.py
@@ -16,4 +16,5 @@ class LibraryFollower(BasePermission):
             return False
 
         library = actors.SYSTEM_ACTORS['library'].get_actor_instance()
-        return library.followers.filter(url=actor.url).exists()
+        return library.received_follows.filter(
+            approved=True, actor=actor).exists()
diff --git a/api/funkwhale_api/federation/serializers.py b/api/funkwhale_api/federation/serializers.py
index b56dd3f44..735a101b4 100644
--- a/api/funkwhale_api/federation/serializers.py
+++ b/api/funkwhale_api/federation/serializers.py
@@ -616,10 +616,12 @@ class CollectionPageSerializer(serializers.Serializer):
         if not item_serializer:
             return v
         raw_items = [item_serializer(data=i, context=self.context) for i in v]
+        valid_items = []
         for i in raw_items:
-            i.is_valid(raise_exception=True)
+            if i.is_valid():
+                valid_items.append(i)
 
-        return raw_items
+        return valid_items
 
     def to_representation(self, conf):
         page = conf['page']
@@ -662,17 +664,17 @@ class CollectionPageSerializer(serializers.Serializer):
 
 
 class ArtistMetadataSerializer(serializers.Serializer):
-    musicbrainz_id = serializers.UUIDField(required=False)
+    musicbrainz_id = serializers.UUIDField(required=False, allow_null=True)
     name = serializers.CharField()
 
 
 class ReleaseMetadataSerializer(serializers.Serializer):
-    musicbrainz_id = serializers.UUIDField(required=False)
+    musicbrainz_id = serializers.UUIDField(required=False, allow_null=True)
     title = serializers.CharField()
 
 
 class RecordingMetadataSerializer(serializers.Serializer):
-    musicbrainz_id = serializers.UUIDField(required=False)
+    musicbrainz_id = serializers.UUIDField(required=False, allow_null=True)
     title = serializers.CharField()
 
 
diff --git a/api/tests/federation/test_permissions.py b/api/tests/federation/test_permissions.py
index 1a6977542..9b8683210 100644
--- a/api/tests/federation/test_permissions.py
+++ b/api/tests/federation/test_permissions.py
@@ -30,11 +30,26 @@ def test_library_follower_actor_non_follower(
     assert check is False
 
 
+def test_library_follower_actor_follower_not_approved(
+        factories, api_request, anonymous_user, settings):
+    settings.FEDERATION_MUSIC_NEEDS_APPROVAL = True
+    library = actors.SYSTEM_ACTORS['library'].get_actor_instance()
+    follow = factories['federation.Follow'](target=library, approved=False)
+    view = APIView.as_view()
+    permission = permissions.LibraryFollower()
+    request = api_request.get('/')
+    setattr(request, 'user', anonymous_user)
+    setattr(request, 'actor', follow.actor)
+    check = permission.has_permission(request, view)
+
+    assert check is False
+
+
 def test_library_follower_actor_follower(
         factories, api_request, anonymous_user, settings):
     settings.FEDERATION_MUSIC_NEEDS_APPROVAL = True
     library = actors.SYSTEM_ACTORS['library'].get_actor_instance()
-    follow = factories['federation.Follow'](target=library)
+    follow = factories['federation.Follow'](target=library, approved=True)
     view = APIView.as_view()
     permission = permissions.LibraryFollower()
     request = api_request.get('/')
diff --git a/api/tests/federation/test_serializers.py b/api/tests/federation/test_serializers.py
index 6d33a529d..85208fa49 100644
--- a/api/tests/federation/test_serializers.py
+++ b/api/tests/federation/test_serializers.py
@@ -431,8 +431,14 @@ def test_collection_page_serializer_validation():
 
 
 def test_collection_page_serializer_can_validate_child():
-    base = 'https://test.federation/test'
     data = {
+        'type': 'CollectionPage',
+        'id': 'https://test.page?page=2',
+        'actor': 'https://test.actor',
+        'first': 'https://test.page?page=1',
+        'last': 'https://test.page?page=3',
+        'partOf': 'https://test.page',
+        'totalItems': 1,
         'items': [{'in': 'valid'}],
     }
 
@@ -441,8 +447,9 @@ def test_collection_page_serializer_can_validate_child():
         context={'item_serializer': serializers.AudioSerializer}
     )
 
-    assert serializer.is_valid() is False
-    assert 'items' in serializer.errors
+    # child are validated but not included in data if not valid
+    assert serializer.is_valid(raise_exception=True) is True
+    assert len(serializer.validated_data['items']) == 0
 
 
 def test_collection_page_serializer(factories):
diff --git a/api/tests/federation/test_views.py b/api/tests/federation/test_views.py
index 8c5235b8b..ae94bcdc0 100644
--- a/api/tests/federation/test_views.py
+++ b/api/tests/federation/test_views.py
@@ -43,7 +43,7 @@ def test_instance_endpoints_405_if_federation_disabled(
 
 
 def test_wellknown_webfinger_validates_resource(
-    db, api_client, settings, mocker):
+        db, api_client, settings, mocker):
     clean = mocker.spy(webfinger, 'clean_resource')
     url = reverse('federation:well-known-webfinger')
     response = api_client.get(url, data={'resource': 'something'})