diff --git a/src/anemoi/datasets/create/config.py b/src/anemoi/datasets/create/config.py
index b761d24..79686f3 100644
--- a/src/anemoi/datasets/create/config.py
+++ b/src/anemoi/datasets/create/config.py
@@ -215,15 +215,14 @@ def _prepare_serialisation(o):
 def set_to_test_mode(cfg):
     NUMBER_OF_DATES = 4
 
-    dates = cfg["dates"]
     LOG.warning(f"Running in test mode. Changing the list of dates to use only {NUMBER_OF_DATES}.")
     groups = Groups(**LoadersConfig(cfg).dates)
 
-    dates = groups.dates
+    dates = groups.provider.values
     cfg["dates"] = dict(
         start=dates[0],
         end=dates[NUMBER_OF_DATES - 1],
-        frequency=dates.frequency,
+        frequency=groups.provider.frequency,
         group_by=NUMBER_OF_DATES,
     )
 
diff --git a/tests/create/test_create.py b/tests/create/test_create.py
index 6e3f381..14e0ffc 100755
--- a/tests/create/test_create.py
+++ b/tests/create/test_create.py
@@ -253,12 +253,13 @@ def compare(self):
 
 @pytest.mark.parametrize("name", NAMES)
 @pytest.mark.skipif(not extensive_tests, reason="Skipping to run the test faster")
+@pytest.mark.parametrize("is_test", [False, True])
 @mockup_from_source
-def test_run(name):
+def test_run(name, is_test=False):
     config = os.path.join(HERE, name + ".yaml")
     output = os.path.join(HERE, name + ".zarr")
 
-    creator_factory("init", config=config, path=output, overwrite=True).run()
+    creator_factory("init", config=config, path=output, overwrite=True, test=is_test).run()
     creator_factory("load", path=output).run()
     creator_factory("finalise", path=output).run()
     creator_factory("patch", path=output).run()