diff --git a/doc/source/tutorial.rst b/doc/source/tutorial.rst
index e857775..388557c 100644
--- a/doc/source/tutorial.rst
+++ b/doc/source/tutorial.rst
@@ -144,6 +144,7 @@ this to a zarr_ store.
 It is then trivial to open this using ``open_datatree``:
 
 .. ipython:: python
+  :okwarning:
 
   dt2 = xarray.open_datatree(zarr_path)
   xarray.testing.assert_identical(dt, dt2)
diff --git a/pyproject.toml b/pyproject.toml
index e312e57..207a6d6 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -6,15 +6,15 @@ authors = ["Simon Perkins <simon.perkins@gmail.com>"]
 readme = "README.rst"
 
 [tool.poetry.dependencies]
-python = "^3.10"
+python = "^3.11"
 pytest = {version = "^8.0.0", optional = true, extras = ["testing"]}
-xarray = "^2025.0"
-dask = {version = "^2024.5.0", optional = true, extras = ["testing"]}
-distributed = {version = "^2024.5.0", optional = true, extras = ["testing"]}
+xarray = "^2025.3"
+dask = {version = "^2025.3.0", optional = true, extras = ["testing"]}
+distributed = {version = "^2025.3.0", optional = true, extras = ["testing"]}
 cacheout = "^0.16.0"
 arcae = "^0.2.8"
 typing-extensions = { version = "^4.12.2", python = "<3.11" }
-zarr = {version = "^2.18.3", optional = true, extras = ["testing"]}
+zarr = {version = "^3.0", optional = true, extras = ["testing"]}
 
 [tool.poetry.extras]
 testing = ["dask", "distributed", "pytest", "zarr"]
@@ -38,8 +38,9 @@ pygments = "^2.18.0"
 sphinx-copybutton = "^0.5.2"
 pydata-sphinx-theme = "^0.15.4"
 ipython = "^8.27.0"
-dask = "^2024.9.0"
-zarr = "^2.18.3"
+dask = "^2025.3.0"
+zarr = "^3.0"
+pickleshare = "^0.7.5"
 
 [tool.ruff]
 line-length = 88
diff --git a/tests/test_zarr_roundtrip.py b/tests/test_zarr_roundtrip.py
index 2eb0215..a6a063d 100644
--- a/tests/test_zarr_roundtrip.py
+++ b/tests/test_zarr_roundtrip.py
@@ -1,18 +1,27 @@
+from contextlib import nullcontext
+
+import pytest
 import xarray.testing as xt
 from xarray.backends.api import open_dataset, open_datatree
 
+ZARR_V3_WARNINGS = (FutureWarning, UserWarning)
+
 
-def test_dataset_roundtrip(simmed_ms, tmp_path):
+@pytest.mark.parametrize("zarr_format", [2, 3])
+def test_dataset_roundtrip(simmed_ms, tmp_path, zarr_format):
   ds = open_dataset(simmed_ms)
   zarr_path = tmp_path / "test_dataset.zarr"
-  ds.to_zarr(zarr_path, compute=True, consolidated=True)
-  ds2 = open_dataset(zarr_path)
+  with pytest.warns(ZARR_V3_WARNINGS) if zarr_format == 3 else nullcontext():
+    ds.to_zarr(zarr_path, compute=True, consolidated=True, zarr_format=zarr_format)
+    ds2 = open_dataset(zarr_path)
   xt.assert_identical(ds, ds2)
 
 
-def test_datatree_roundtrip(simmed_ms, tmp_path):
+@pytest.mark.parametrize("zarr_format", [2, 3])
+def test_datatree_roundtrip(simmed_ms, tmp_path, zarr_format):
   dt = open_datatree(simmed_ms)
   zarr_path = tmp_path / "test_datatree.zarr"
-  dt.to_zarr(zarr_path, compute=True, consolidated=True)
-  dt2 = open_datatree(zarr_path)
+  with pytest.warns(ZARR_V3_WARNINGS) if zarr_format == 3 else nullcontext():
+    dt.to_zarr(zarr_path, compute=True, consolidated=True, zarr_format=zarr_format)
+    dt2 = open_datatree(zarr_path)
   xt.assert_identical(dt, dt2)
diff --git a/xarray_ms/backend/msv2/factories/antenna.py b/xarray_ms/backend/msv2/factories/antenna.py
index aea9cfa..f91f61c 100644
--- a/xarray_ms/backend/msv2/factories/antenna.py
+++ b/xarray_ms/backend/msv2/factories/antenna.py
@@ -87,7 +87,7 @@ def get_dataset(self) -> Mapping[str, Variable]:
     pol_type = (
       pac.list_flatten(filtered_feeds["POLARIZATION_TYPE"]).to_numpy().reshape(-1, 2)
     )
-    receptor_labels = [f"pol_{i}" for i in range(nreceptors.item())]
+    receptor_labels = np.asarray([f"pol_{i}" for i in range(nreceptors.item())], object)
 
     metre_attrs = {"units": ["m"], "type": "quantity"}
     rad_attrs = {"units": ["rad"], "type": "quantity"}
@@ -123,7 +123,9 @@ def get_dataset(self) -> Mapping[str, Variable]:
         "mount": Variable("antenna_name", mount),
         "telescope_name": Variable("telescope_name", telescope_names),
         "station": Variable("antenna_name", station),
-        "cartesian_pos_label": Variable("cartesian_pos_label", ["x", "y", "z"]),
+        "cartesian_pos_label": Variable(
+          "cartesian_pos_label", np.asarray(["x", "y", "z"], object)
+        ),
         "polarization_type": Variable(("antenna_name", "receptor_label"), pol_type),
         "receptor_label": Variable("receptor_label", receptor_labels),
       },
diff --git a/xarray_ms/backend/msv2/factories/correlated.py b/xarray_ms/backend/msv2/factories/correlated.py
index c5cc70a..c5a885f 100644
--- a/xarray_ms/backend/msv2/factories/correlated.py
+++ b/xarray_ms/backend/msv2/factories/correlated.py
@@ -244,8 +244,8 @@ def get_variables(self) -> Mapping[str, Variable]:
         "baseline_antenna2_name",
         (("baseline_id",), ant2_names, {"coordinates": "baseline_antenna2_name"}),
       ),
-      ("polarization", (("polarization",), corr_type, None)),
-      ("uvw_label", (("uvw_label",), ["u", "v", "w"], None)),
+      ("polarization", (("polarization",), np.asarray(corr_type, object), None)),
+      ("uvw_label", (("uvw_label",), np.asarray(["u", "v", "w"], object), None)),
       ("field_name", ("time", field_names, {"coordinates": "field_name"})),
       ("scan_number", ("time", partition.scan_numbers, {"coordinates": "scan_number"})),
       (