diff --git a/omnipath/_core/downloader/_downloader.py b/omnipath/_core/downloader/_downloader.py
index bda83f3..71f0bbe 100644
--- a/omnipath/_core/downloader/_downloader.py
+++ b/omnipath/_core/downloader/_downloader.py
@@ -142,8 +142,8 @@ def maybe_download(
                 try:
                     res = self._download(req)
                 except RequestException:
-                    logging.warn(f"Failed to download from `{domain}`.")
-                    logging.warn(traceback.format_exc())
+                    logging.warning(f"Failed to download from `{domain}`.")
+                    logging.warning(traceback.format_exc())
                     continue
                 res = callback(res)
                 if cache:
diff --git a/tests/test_downloader.py b/tests/test_downloader.py
index 3fab46b..12e9bee 100644
--- a/tests/test_downloader.py
+++ b/tests/test_downloader.py
@@ -166,7 +166,7 @@ def test_fallback_urls(self, requests_mock, csv_data: bytes):
         downloader = Downloader(opt)
         res = downloader.maybe_download(query, callback=pd.read_csv)
 
-        assert requests_mock.called_once
+        assert requests_mock.called
         np.testing.assert_array_equal(res.index, csv_df.index)
         np.testing.assert_array_equal(res.columns, csv_df.columns)
         np.testing.assert_array_equal(res.values, csv_df.values)
diff --git a/tests/test_requests.py b/tests/test_requests.py
index 13f983c..4a14c68 100644
--- a/tests/test_requests.py
+++ b/tests/test_requests.py
@@ -6,7 +6,7 @@
 
 import pytest
 
-from pandas.api.types import is_object_dtype, is_categorical_dtype
+from pandas.api.types import is_object_dtype
 import numpy as np
 import pandas as pd
 
@@ -144,7 +144,7 @@ def test_no_dtype_conversion(self, cache_backup, requests_mock, tsv_data: bytes)
         options.convert_dtypes = True
 
         res = Enzsub.get()
-        assert is_categorical_dtype(res["modification"])
+        assert isinstance(res["modification"].dtype, pd.CategoricalDtype)
         assert requests_mock.called_once