diff --git a/tests/conftest.py b/tests/conftest.py
index 49bd5a8..7e7e4fb 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -49,3 +49,9 @@ def simple_zarr() -> pystac.Asset:
         catalog = pystac_client.Client.open(STAC_URLS["PLANETARY-COMPUTER"])
         collection = catalog.get_collection("daymet-daily-hi")
         return collection.assets["zarr-abfs"]
+
+
+@pytest.fixture(scope="module")
+def complex_zarr(simple_zarr) -> pystac.Asset:
+    simple_zarr.extra_fields["xarray:open_kwargs"]["engine"] = "zarr"
+    return simple_zarr
diff --git a/tests/test_core.py b/tests/test_core.py
index e8c13e8..bb6559a 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -30,4 +30,9 @@ def test_to_xarray_reference_file(simple_reference_file):
 
 def test_to_xarray_zarr(simple_zarr):
     ds = to_xarray(simple_zarr)
-    ds
+    assert ds
+
+
+def test_to_xarray_zarr_with_open_kwargs_engine(complex_zarr):
+    ds = to_xarray(complex_zarr)
+    assert ds
diff --git a/xpystac/core.py b/xpystac/core.py
index f825b44..4d5a18c 100644
--- a/xpystac/core.py
+++ b/xpystac/core.py
@@ -64,5 +64,5 @@ def _(obj: pystac.Asset, **kwargs) -> xarray.Dataset:
     else:
         default_kwargs = {}
 
-    ds = xarray.open_dataset(obj.href, **default_kwargs, **open_kwargs, **kwargs)
+    ds = xarray.open_dataset(obj.href, **{**default_kwargs, **open_kwargs, **kwargs})
     return ds