diff --git a/torchhd/tests/test_similarities.py b/torchhd/tests/test_similarities.py
index 46807a4c..e34124f8 100644
--- a/torchhd/tests/test_similarities.py
+++ b/torchhd/tests/test_similarities.py
@@ -279,6 +279,7 @@ def test_device(self, dtype):
 
         assert similarity.device == device
 
+
 class TestHammingSimilarity:
     @pytest.mark.parametrize("dtype", torch_dtypes)
     def test_shape(self, dtype):