diff --git a/cf2cdm/cfcoords.py b/cf2cdm/cfcoords.py
index 4278b80..f9d6088 100644
--- a/cf2cdm/cfcoords.py
+++ b/cf2cdm/cfcoords.py
@@ -19,22 +19,25 @@
 
 import functools
 import logging
-import typing as T
+from typing import Any, Callable, Dict, Hashable, List, Mapping
 
 import xarray as xr
 
 from . import cfunits
 
-CoordModelType = T.Dict[str, T.Dict[str, str]]
-CoordTranslatorType = T.Callable[[str, xr.Dataset, CoordModelType], xr.Dataset]
+# force ruff to keep comment types
+_ = [Any, Mapping, Hashable, List]
+
+CoordModelType = Dict[str, Dict[str, str]]
+CoordTranslatorType = Callable[[str, xr.Dataset, CoordModelType], xr.Dataset]
 
 COORD_MODEL: CoordModelType = {}
-COORD_TRANSLATORS: T.Dict[str, CoordTranslatorType] = {}
+COORD_TRANSLATORS: Dict[str, CoordTranslatorType] = {}
 LOG = logging.getLogger(__name__)
 
 
 def match_values(match_value_func, mapping):
-    # type: (T.Callable[[T.Any], bool], T.Mapping[T.Hashable, T.Any]) -> T.List[str]
+    # type: (Callable[[Any], bool], Mapping[Hashable, Any]) -> List[str]
     matched_names = []
     for name, value in mapping.items():
         if match_value_func(value):
@@ -60,7 +63,7 @@ def coord_translator(
     default_out_name: str,
     default_units: str,
     default_direction: str,
-    is_cf_type: T.Callable[[xr.IndexVariable], bool],
+    is_cf_type: Callable[[xr.IndexVariable], bool],
     cf_type: str,
     data: xr.Dataset,
     coord_model: CoordModelType = COORD_MODEL,
@@ -206,7 +209,7 @@ def is_forecast_month(coord: xr.IndexVariable) -> bool:
 def translate_coords(
     data, coord_model=COORD_MODEL, errors="warn", coord_translators=COORD_TRANSLATORS
 ):
-    # type: (xr.Dataset, CoordModelType, str, T.Dict[str, CoordTranslatorType]) -> xr.Dataset
+    # type: (xr.Dataset, CoordModelType, str, Dict[str, CoordTranslatorType]) -> xr.Dataset
     for cf_name, translator in coord_translators.items():
         try:
             data = translator(cf_name, data, coord_model)
diff --git a/pyproject.toml b/pyproject.toml
index fd5140a..fdb9069 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -13,6 +13,7 @@ classifiers = [
   "Programming Language :: Python :: 3.11",
   "Topic :: Scientific/Engineering"
 ]
+dependencies = ["xarray"]
 description = "Translate xarray dataset to a custom data model"
 dynamic = ["version"]
 license = {file = "LICENSE"}
diff --git a/tests/test_20_cfcoords.py b/tests/test_20_cfcoords.py
index b4fb186..29e98c3 100644
--- a/tests/test_20_cfcoords.py
+++ b/tests/test_20_cfcoords.py
@@ -1,4 +1,5 @@
 import sys
+from typing import Any, Dict, Hashable
 
 import numpy as np
 import pytest
@@ -77,7 +78,7 @@ def da3() -> xr.Dataset:
 
 
 def test_match_values() -> None:
-    mapping = {"callable": len, "int": 1}  # type: T.Dict[T.Hashable, T.Any]
+    mapping: Dict[Hashable, Any] = {"callable": len, "int": 1}
     res = cfcoords.match_values(callable, mapping)
 
     assert res == ["callable"]
diff --git a/tests/test_50_datamodels.py b/tests/test_50_datamodels.py
index 1442e21..f075d8d 100644
--- a/tests/test_50_datamodels.py
+++ b/tests/test_50_datamodels.py
@@ -1,6 +1,6 @@
 import os.path
 
-from cfgrib import xarray_store
+import xarray as xr
 
 from cf2cdm import cfcoords, datamodels
 
@@ -10,7 +10,7 @@
 
 
 def test_cds() -> None:
-    ds = xarray_store.open_dataset(TEST_DATA1)
+    ds = xr.open_dataset(TEST_DATA1)
 
     res = cfcoords.translate_coords(ds, coord_model=datamodels.CDS)
 
@@ -31,7 +31,7 @@ def test_cds() -> None:
         "time",
     }
 
-    ds = xarray_store.open_dataset(TEST_DATA2)
+    ds = xr.open_dataset(TEST_DATA2)
 
     res = cfcoords.translate_coords(ds, coord_model=datamodels.CDS)
 
@@ -47,7 +47,7 @@ def test_cds() -> None:
 
 
 def test_ecmwf() -> None:
-    ds = xarray_store.open_dataset(TEST_DATA1)
+    ds = xr.open_dataset(TEST_DATA1)
 
     res = cfcoords.translate_coords(ds, coord_model=datamodels.ECMWF)
 
@@ -62,7 +62,7 @@ def test_ecmwf() -> None:
         "valid_time",
     }
 
-    ds = xarray_store.open_dataset(TEST_DATA2)
+    ds = xr.open_dataset(TEST_DATA2)
 
     res = cfcoords.translate_coords(ds, coord_model=datamodels.ECMWF)