diff --git a/skchange/anomaly_detectors/tests/test_anomaly_detectors.py b/skchange/anomaly_detectors/tests/test_anomaly_detectors.py
index 6c2d96ac..c0adfe45 100644
--- a/skchange/anomaly_detectors/tests/test_anomaly_detectors.py
+++ b/skchange/anomaly_detectors/tests/test_anomaly_detectors.py
@@ -3,8 +3,11 @@
 import pandas as pd
 import pytest
 
-from skchange.anomaly_detectors import ANOMALY_DETECTORS, COLLECTIVE_ANOMALY_DETECTORS
-from skchange.anomaly_detectors import MoscoreAnomaly
+from skchange.anomaly_detectors import (
+    ANOMALY_DETECTORS,
+    COLLECTIVE_ANOMALY_DETECTORS,
+    MoscoreAnomaly,
+)
 from skchange.anomaly_detectors.base import CollectiveAnomalyDetector
 from skchange.datasets.generate import generate_anomalous_data
 from skchange.scores.mean_score import init_mean_score, mean_anomaly_score
diff --git a/skchange/costs/tests/test_costs.py b/skchange/costs/tests/test_costs.py
index 7de87cca..83de9374 100644
--- a/skchange/costs/tests/test_costs.py
+++ b/skchange/costs/tests/test_costs.py
@@ -32,5 +32,3 @@ def cost_f(params: np.ndarray, start: int, end: int, split: int) -> float:
     assert init_cost_f(np.zeros(1)) == np.zeros(1)
     assert cost_f(np.zeros(1), 0, 1, 0) == 10.0
     assert (cost_f, init_cost_f) == cost_factory((cost_f, init_cost_f))
-
-
diff --git a/skchange/costs/tests/test_savings.py b/skchange/costs/tests/test_savings.py
index cc3f80eb..4514b65f 100644
--- a/skchange/costs/tests/test_savings.py
+++ b/skchange/costs/tests/test_savings.py
@@ -21,6 +21,7 @@ def test_savings(savings):
 
 def test_custom_savings():
     """Test custom savings."""
+
     def init_savings_f(X: np.ndarray) -> np.ndarray:
         return X
 
diff --git a/skchange/utils/numba/__init__.py b/skchange/utils/numba/__init__.py
index 4665a879..53756a60 100644
--- a/skchange/utils/numba/__init__.py
+++ b/skchange/utils/numba/__init__.py
@@ -1,2 +1,3 @@
 """Numba utility functions."""
+
 from .soft_import import jit, njit, prange
diff --git a/skchange/utils/numba/general.py b/skchange/utils/numba/general.py
index ac715cbc..e7a26365 100644
--- a/skchange/utils/numba/general.py
+++ b/skchange/utils/numba/general.py
@@ -1,4 +1,4 @@
-"""Numba-optimized functions for various common data manipulation tasks.""" ""
+"""Numba-optimized functions for various common data manipulation tasks."""
 
 import numpy as np