diff --git a/darts/tests/datasets/test_datasets.py b/darts/tests/datasets/test_datasets.py
index 52d2e0d8df..92b37f105b 100644
--- a/darts/tests/datasets/test_datasets.py
+++ b/darts/tests/datasets/test_datasets.py
@@ -507,7 +507,7 @@ def test_inference_dataset_output_chunk_shift(self, config):
             target = self.target1[: -(ocl + ocs)]
 
             ds_covs = {}
-            ds_init_params = set(inspect.signature(ds_cls).parameters)
+            ds_init_params = set(inspect.signature(ds_cls.__init__).parameters)
             for cov_type in ["covariates", "past_covariates", "future_covariates"]:
                 if cov_type in ds_init_params:
                     ds_covs[cov_type] = self.cov1
@@ -1388,7 +1388,7 @@ def test_sequential_training_dataset_output_chunk_shift(self, config):
             target = self.target1[: -(ocl + ocs)]
 
             ds_covs = {}
-            ds_init_params = set(inspect.signature(ds_cls).parameters)
+            ds_init_params = set(inspect.signature(ds_cls.__init__).parameters)
             for cov_type in ["covariates", "past_covariates", "future_covariates"]:
                 if cov_type in ds_init_params:
                     ds_covs[cov_type] = self.cov1