diff --git a/spectral_cube/dask_spectral_cube.py b/spectral_cube/dask_spectral_cube.py
index 4884f63fa..555f79d8b 100644
--- a/spectral_cube/dask_spectral_cube.py
+++ b/spectral_cube/dask_spectral_cube.py
@@ -80,7 +80,7 @@ def wrapper(self, *args, **kwargs):
                 raise ImportError("saving the cube to a temporary directory "
                                   "requires the zarr and fsspec packages to "
                                   "be installed.")
-            filename = tempfile.mkstemp()
+            filenum, filename = tempfile.mkstemp()
             with dask.config.set(**cube._scheduler_kwargs):
                 cube._data.to_zarr(filename)
             cube._data = da.from_zarr(filename)