diff --git a/river/compat/sklearn_to_river.py b/river/compat/sklearn_to_river.py
index bb16ad76c7..93664bd342 100644
--- a/river/compat/sklearn_to_river.py
+++ b/river/compat/sklearn_to_river.py
@@ -33,7 +33,7 @@ def convert_sklearn_to_river(estimator: sklearn_base.BaseEstimator, classes: lis
         (sklearn_base.RegressorMixin, SKL2RiverRegressor),
         (
             sklearn_base.ClassifierMixin,
-            functools.partial(SKL2RiverClassifier, classes=classes),
+            functools.partial(SKL2RiverClassifier, classes=classes),  # type:ignore[arg-type]
         ),
     ]
 
diff --git a/river/feature_extraction/vectorize.py b/river/feature_extraction/vectorize.py
index f4d6aff840..5f68450208 100644
--- a/river/feature_extraction/vectorize.py
+++ b/river/feature_extraction/vectorize.py
@@ -203,7 +203,7 @@ def __init__(
         # Stop word removal
         if self.stop_words:
             self.processing_steps.append(
-                functools.partial(remove_stop_words, stop_words=stop_words)
+                functools.partial(remove_stop_words, stop_words=self.stop_words)
             )
 
         # n-grams