diff --git a/virtualizarr/tests/test_readers/test_zarr.py b/virtualizarr/tests/test_readers/test_zarr.py
index ce45d4fe..15e92801 100644
--- a/virtualizarr/tests/test_readers/test_zarr.py
+++ b/virtualizarr/tests/test_readers/test_zarr.py
@@ -78,7 +78,6 @@ def _validate_v2(attrs: list[str]):
                     assert vds_attr == zarr_metadata_attr
 
         def _validate_v3(attrs: list[str]):
-
             # check v2, v3 shared attrs
             for array in arrays:
                 for attr in attrs:
@@ -117,4 +116,4 @@ def _validate_v3(attrs: list[str]):
             _validate_v3(shared_v2_v3_attrs)
 
         else:
-            raise NotImplementedError(f'Zarr format {zarr_format} not in [2,3]')
+            raise NotImplementedError(f"Zarr format {zarr_format} not in [2,3]")