diff --git a/esm-collections/cloud-access/dkrz_era5_disk.json b/esm-collections/cloud-access/dkrz_era5_disk.json
index 9048b4c088f3fbdda0564e897371b074e5fdc99d..f054dc16c14568ccc0991a1ff64166be2f1310b2 100755
--- a/esm-collections/cloud-access/dkrz_era5_disk.json
+++ b/esm-collections/cloud-access/dkrz_era5_disk.json
@@ -117,10 +117,11 @@
         ],
         "variable_column_name": "short_name",
         "groupby_attrs": [
+	    "era_id",
             "table_id",
             "stepType",
             "level_type",
             "frequency"
         ]
     }
-}
\ No newline at end of file
+}