diff --git a/beets/library/models.py b/beets/library/models.py
index 971a2b517..69daeade3 100644
--- a/beets/library/models.py
+++ b/beets/library/models.py
@@ -364,7 +364,8 @@ class Album(LibModel):
         media_set = {
             str(item.media)
             for item in self.items()
-            if getattr(item, "media", None)}
+            if getattr(item, "media", None)
+        }
         return list(media_set)
 
     @classmethod
diff --git a/test/test_media_field.py b/test/test_media_field.py
index aac6ae2c6..e2410c6ad 100644
--- a/test/test_media_field.py
+++ b/test/test_media_field.py
@@ -5,7 +5,7 @@ from beets.library import Item, Library
 
 class MediaFieldTest(unittest.TestCase):
     def setUp(self):
-        self.lib = Library(':memory:')
+        self.lib = Library(":memory:")
         self.lib.add_album = self.lib.add_album
 
     def add_album_with_items(self, items_data):
@@ -23,7 +23,7 @@ class MediaFieldTest(unittest.TestCase):
         ]
         album = self.add_album_with_items(items_data)
         media = album.media
-        assert media == ["CD", "Vinyl"]
+        assert sorted(media) == ["CD", "Vinyl"]
 
     def test_album_media_field_single_type(self):
         items_data = [