diff --git a/mopidy/models.py b/mopidy/models.py
index 03f991ab..f4404fb8 100644
--- a/mopidy/models.py
+++ b/mopidy/models.py
@@ -150,9 +150,8 @@ class ImmutableObjectMeta(type):
         attrs['_instances'] = weakref.WeakValueDictionary()
         attrs['__slots__'] = ['_hash'] + fields.values()
 
-        anncestors = [b for base in bases for b in inspect.getmro(base)]
-        for anncestor in anncestors:
-            if '__weakref__' in getattr(anncestor, '__slots__', []):
+        for ancestor in [b for base in bases for b in inspect.getmro(base)]:
+            if '__weakref__' in getattr(ancestor, '__slots__', []):
                 break
         else:
             attrs['__slots__'].append('__weakref__')
diff --git a/tests/models/test_models.py b/tests/models/test_models.py
index 27d02382..c9c91ba1 100644
--- a/tests/models/test_models.py
+++ b/tests/models/test_models.py
@@ -8,7 +8,7 @@ from mopidy.models import (
     TlTrack, Track, model_json_decoder)
 
 
-class InheritanecTest(unittest.TestCase):
+class InheritanceTest(unittest.TestCase):
 
     def test_weakref_and_slots_play_nice_in_subclass(self):
         # Check that the following does not happen: