diff --git a/climetlab/utils/grib.py b/climetlab/utils/grib.py
index 2601184d..34995dab 100644
--- a/climetlab/utils/grib.py
+++ b/climetlab/utils/grib.py
@@ -22,6 +22,7 @@ def post_xarray_open_dataset_hook(ds):
         ds = ds.drop("surface")
     return ds
 
+
 def open_dataset_params(time_convention="withstep"):
     params = {}
     if time_convention == "withstep":
@@ -51,4 +52,4 @@ def open_dataset_params(time_convention="withstep"):
     params["chunks"] = chunk_sizes_in
     params["backend_kwargs"] = dict(squeeze=False, time_dims=time_dims)
 
-    return params
\ No newline at end of file
+    return params