diff --git a/cfgrib/dataset.py b/cfgrib/dataset.py
index d87f1b53..f4054d1c 100644
--- a/cfgrib/dataset.py
+++ b/cfgrib/dataset.py
@@ -463,8 +463,7 @@ def encode_cf_first(data_var_attrs, encode_cf=("parameter", "time"), time_dims=(
             raise ValueError("time_dims %r not a subset of %r" % (time_dims, ALL_REF_TIME_KEYS))
     else:
         coords_map.extend(DATA_TIME_KEYS)
-    if "level" in encode_cf:
-        coords_map.extend(VERTICAL_KEYS)
+    coords_map.extend(VERTICAL_KEYS)
     coords_map.extend(SPECTRA_KEYS)
     return coords_map
 
diff --git a/tests/test_30_dataset.py b/tests/test_30_dataset.py
index 83f0392f..08329b5a 100644
--- a/tests/test_30_dataset.py
+++ b/tests/test_30_dataset.py
@@ -135,7 +135,7 @@ def test_build_dataset_components_ignore_keys() -> None:
     stream = messages.FileStream(TEST_DATA_UKMO, "warn")
     index = dataset.open_fileindex(stream, messages.DEFAULT_INDEXPATH, dataset.INDEX_KEYS)
     assert "subCentre" in index.index_keys
-    index = dataset.open_fileindex(stream, messages.DEFAULT_INDEXPATH, index_keys, ignore_keys=["subCentre"])
+    index = dataset.open_fileindex(stream, messages.DEFAULT_INDEXPATH, dataset.INDEX_KEYS, ignore_keys=["subCentre"])
     assert "subCentre" not in index.index_keys
 
 def test_Dataset() -> None: