diff --git a/pyproject.toml b/pyproject.toml
index ad2bb6b..26a69ea 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -20,14 +20,14 @@ classifiers = [
     "License :: OSI Approved :: MIT License",
 ]
 dependencies = [
-    "fsspec==2024.6.1",
+    "fsspec==2025.7.0",
     "huggingface-hub==0.28.1",
     "hydra-core==1.3.2",
     "loguru == 0.7.3",
     "numpy==2.1.2",
-    "ocf-data-sampler==0.1.4",
+    "ocf-data-sampler==0.5.5",
     "pandas==2.2.3",
-    "s3fs==2024.6.1",
+    "s3fs==2025.7.0",
     "safetensors==0.5.2",
     "sat_pred @ git+https://github.com/openclimatefix/sat_pred.git@main",
     # Since torch distributes CPU only packages as wheels, have to specify the target platform in order to pull the wheel compiled for that specific platform
@@ -36,8 +36,8 @@ dependencies = [
     "torch @ https://download.pytorch.org/whl/cpu/torch-2.3.1%2Bcpu-cp312-cp312-linux_x86_64.whl ; platform_system == 'Linux' and platform_machine == 'x86_64'",
     "torchvision @ https://download.pytorch.org/whl/cpu/torchvision-0.18.1%2Bcpu-cp312-cp312-linux_x86_64.whl ; platform_system == 'Linux' and platform_machine == 'x86_64'",
     "typer==0.15.1",
-    "xarray==2025.1.2",
-    "zarr==2.18.3",
+    "xarray==2025.7.1",
+    "zarr==3.1.1",
 ]
 
 [dependency-groups]
diff --git a/tests/conftest.py b/tests/conftest.py
index 40b65bb..789735d 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -5,20 +5,21 @@
 import pandas as pd
 import pytest
 import xarray as xr
+import zarr
 
 xr.set_options(keep_attrs=True)
 
 @pytest.fixture()
 def test_t0():
-    return pd.Timestamp.now(tz=None).floor("30min")
+    return pd.Timestamp.now(tz="UTC").replace(tzinfo=None).floor("30min")
 
 
 def make_sat_data(test_t0, freq_mins):
 
     # Load dataset which only contains coordinates, but no data
     shell_path = f"{os.path.dirname(os.path.abspath(__file__))}/test_data/non_hrv_shell.zarr.zip"
-
-    ds = xr.open_zarr(fsspec.get_mapper(f"zip::{shell_path}"))
+    with zarr.storage.ZipStore(shell_path, mode="r") as store:
+        ds = xr.open_zarr(store)
 
     # Remove original time dim
     ds = ds.drop_vars("time")
@@ -41,6 +42,11 @@ def make_sat_data(test_t0, freq_mins):
     ds.data.attrs = ds.attrs["_data_attrs"]
     del ds.attrs["_data_attrs"]
 
+
+    # # This is important to avoid saving errors
+    for v in list(ds.variables.keys()):
+        ds[v].encoding.clear()
+
     return ds
 
 
diff --git a/tests/test_app.py b/tests/test_app.py
index c763ed7..f984ec6 100644
--- a/tests/test_app.py
+++ b/tests/test_app.py
@@ -32,7 +32,7 @@ def test_app(sat_5_data, tmp_path, test_t0):
 
     assert "sat_pred" in  ds_y_hat
     assert (
-        list(ds_y_hat.sat_pred.coords)==
+        sorted(list(ds_y_hat.sat_pred.coords))==
         ["init_time", "step", "variable", "x_geostationary", "y_geostationary"]
     )