Backport https://github.com/beetbox/mediafile/commit/b3343c4ee08d1251ae5e2344401a2f5892b4e868
to Beets 1.4.9.

diff --git i/setup.py w/setup.py
index 79278f8..b8d6068 100755
--- i/setup.py
+++ w/setup.py
@@ -87,7 +87,7 @@ setup(
 
     install_requires=[
         'six>=1.9',
-        'mutagen>=1.33',
+        'mutagen>=1.43',
         'unidecode',
         'musicbrainzngs>=0.4',
         'pyyaml',
diff --git i/test/test_mediafile.py w/test/test_mediafile.py
index 36a2c53..54ef9dd 100644
--- i/test/test_mediafile.py
+++ w/test/test_mediafile.py
@@ -912,7 +912,7 @@ class AIFFTest(ReadWriteTestBase, unittest.TestCase):
         'bitrate': 705600,
         'format': u'AIFF',
         'samplerate': 44100,
-        'bitdepth': 0,
+        'bitdepth': 16,
         'channels': 1,
     }