diff --git a/ome_zarr/utils.py b/ome_zarr/utils.py
index 086ede3d..c929c283 100644
--- a/ome_zarr/utils.py
+++ b/ome_zarr/utils.py
@@ -129,7 +129,9 @@ def download(input_path: str, output_dir: str = ".") -> None:
                     for dataset, data in reversed(list(zip(datasets, resolutions))):
                         LOGGER.info("resolution %s...", dataset)
                         with pbar:
-                            data.to_zarr(str(target_path / dataset))
+                            data.to_zarr(
+                                str(target_path / dataset), dimension_separator="/"
+                            )
             else:
                 # Assume a group that needs metadata, like labels
                 zarr.group(str(target_path))
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 59c4650f..b38aba46 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -8,6 +8,16 @@
 from ome_zarr.utils import strip_common_prefix
 
 
+def directory_items(directory: Path):
+    """
+    Get all items (files and folders) in a directory, relative to that directory.
+    """
+    if not directory.is_dir():
+        raise ValueError(f"{directory} is not a directory")
+
+    return sorted([p.relative_to(directory) for p in directory.glob("*")])
+
+
 class TestCli:
     @pytest.fixture(autouse=True)
     def initdir(self, tmpdir):
@@ -40,9 +50,7 @@ def test_astronaut_download(self, tmpdir):
         main(["download", filename, f"--output={out}"])
         main(["info", f"{out}/{basename}"])
 
-        out_path = Path(out) / "data-3"
-        paths = [p.relative_to(out_path) for p in out_path.glob("*")]
-        assert sorted(paths) == [
+        assert directory_items(Path(out) / "data-3") == [
             Path(".zattrs"),
             Path(".zgroup"),
             Path("0"),
@@ -53,202 +61,11 @@ def test_astronaut_download(self, tmpdir):
             Path("labels"),
         ]
 
-        data_path = Path(out) / "data-3" / "1"
-        paths = [p.relative_to(data_path) for p in data_path.glob("*")]
-        assert sorted(paths) == [
+        assert directory_items(Path(out) / "data-3" / "1") == [
             Path(".zarray"),
-            Path("0.0.0"),
-            Path("0.0.1"),
-            Path("0.0.2"),
-            Path("0.0.3"),
-            Path("0.0.4"),
-            Path("0.0.5"),
-            Path("0.0.6"),
-            Path("0.0.7"),
-            Path("0.1.0"),
-            Path("0.1.1"),
-            Path("0.1.2"),
-            Path("0.1.3"),
-            Path("0.1.4"),
-            Path("0.1.5"),
-            Path("0.1.6"),
-            Path("0.1.7"),
-            Path("0.2.0"),
-            Path("0.2.1"),
-            Path("0.2.2"),
-            Path("0.2.3"),
-            Path("0.2.4"),
-            Path("0.2.5"),
-            Path("0.2.6"),
-            Path("0.2.7"),
-            Path("0.3.0"),
-            Path("0.3.1"),
-            Path("0.3.2"),
-            Path("0.3.3"),
-            Path("0.3.4"),
-            Path("0.3.5"),
-            Path("0.3.6"),
-            Path("0.3.7"),
-            Path("0.4.0"),
-            Path("0.4.1"),
-            Path("0.4.2"),
-            Path("0.4.3"),
-            Path("0.4.4"),
-            Path("0.4.5"),
-            Path("0.4.6"),
-            Path("0.4.7"),
-            Path("0.5.0"),
-            Path("0.5.1"),
-            Path("0.5.2"),
-            Path("0.5.3"),
-            Path("0.5.4"),
-            Path("0.5.5"),
-            Path("0.5.6"),
-            Path("0.5.7"),
-            Path("0.6.0"),
-            Path("0.6.1"),
-            Path("0.6.2"),
-            Path("0.6.3"),
-            Path("0.6.4"),
-            Path("0.6.5"),
-            Path("0.6.6"),
-            Path("0.6.7"),
-            Path("0.7.0"),
-            Path("0.7.1"),
-            Path("0.7.2"),
-            Path("0.7.3"),
-            Path("0.7.4"),
-            Path("0.7.5"),
-            Path("0.7.6"),
-            Path("0.7.7"),
-            Path("1.0.0"),
-            Path("1.0.1"),
-            Path("1.0.2"),
-            Path("1.0.3"),
-            Path("1.0.4"),
-            Path("1.0.5"),
-            Path("1.0.6"),
-            Path("1.0.7"),
-            Path("1.1.0"),
-            Path("1.1.1"),
-            Path("1.1.2"),
-            Path("1.1.3"),
-            Path("1.1.4"),
-            Path("1.1.5"),
-            Path("1.1.6"),
-            Path("1.1.7"),
-            Path("1.2.0"),
-            Path("1.2.1"),
-            Path("1.2.2"),
-            Path("1.2.3"),
-            Path("1.2.4"),
-            Path("1.2.5"),
-            Path("1.2.6"),
-            Path("1.2.7"),
-            Path("1.3.0"),
-            Path("1.3.1"),
-            Path("1.3.2"),
-            Path("1.3.3"),
-            Path("1.3.4"),
-            Path("1.3.5"),
-            Path("1.3.6"),
-            Path("1.3.7"),
-            Path("1.4.0"),
-            Path("1.4.1"),
-            Path("1.4.2"),
-            Path("1.4.3"),
-            Path("1.4.4"),
-            Path("1.4.5"),
-            Path("1.4.6"),
-            Path("1.4.7"),
-            Path("1.5.0"),
-            Path("1.5.1"),
-            Path("1.5.2"),
-            Path("1.5.3"),
-            Path("1.5.4"),
-            Path("1.5.5"),
-            Path("1.5.6"),
-            Path("1.5.7"),
-            Path("1.6.0"),
-            Path("1.6.1"),
-            Path("1.6.2"),
-            Path("1.6.3"),
-            Path("1.6.4"),
-            Path("1.6.5"),
-            Path("1.6.6"),
-            Path("1.6.7"),
-            Path("1.7.0"),
-            Path("1.7.1"),
-            Path("1.7.2"),
-            Path("1.7.3"),
-            Path("1.7.4"),
-            Path("1.7.5"),
-            Path("1.7.6"),
-            Path("1.7.7"),
-            Path("2.0.0"),
-            Path("2.0.1"),
-            Path("2.0.2"),
-            Path("2.0.3"),
-            Path("2.0.4"),
-            Path("2.0.5"),
-            Path("2.0.6"),
-            Path("2.0.7"),
-            Path("2.1.0"),
-            Path("2.1.1"),
-            Path("2.1.2"),
-            Path("2.1.3"),
-            Path("2.1.4"),
-            Path("2.1.5"),
-            Path("2.1.6"),
-            Path("2.1.7"),
-            Path("2.2.0"),
-            Path("2.2.1"),
-            Path("2.2.2"),
-            Path("2.2.3"),
-            Path("2.2.4"),
-            Path("2.2.5"),
-            Path("2.2.6"),
-            Path("2.2.7"),
-            Path("2.3.0"),
-            Path("2.3.1"),
-            Path("2.3.2"),
-            Path("2.3.3"),
-            Path("2.3.4"),
-            Path("2.3.5"),
-            Path("2.3.6"),
-            Path("2.3.7"),
-            Path("2.4.0"),
-            Path("2.4.1"),
-            Path("2.4.2"),
-            Path("2.4.3"),
-            Path("2.4.4"),
-            Path("2.4.5"),
-            Path("2.4.6"),
-            Path("2.4.7"),
-            Path("2.5.0"),
-            Path("2.5.1"),
-            Path("2.5.2"),
-            Path("2.5.3"),
-            Path("2.5.4"),
-            Path("2.5.5"),
-            Path("2.5.6"),
-            Path("2.5.7"),
-            Path("2.6.0"),
-            Path("2.6.1"),
-            Path("2.6.2"),
-            Path("2.6.3"),
-            Path("2.6.4"),
-            Path("2.6.5"),
-            Path("2.6.6"),
-            Path("2.6.7"),
-            Path("2.7.0"),
-            Path("2.7.1"),
-            Path("2.7.2"),
-            Path("2.7.3"),
-            Path("2.7.4"),
-            Path("2.7.5"),
-            Path("2.7.6"),
-            Path("2.7.7"),
+            Path("0"),
+            Path("1"),
+            Path("2"),
         ]
 
     def test_s3_info(self, s3_address):