diff --git a/test/conftest.py b/test/conftest.py
index 8b618cb3b..13a0d1a9f 100644
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -6,6 +6,7 @@
 # coding: utf-8
 
 import pathlib
+
 import pypsa
 import pytest
 import yaml
diff --git a/test/test_build_powerplants.py b/test/test_build_powerplants.py
index 60f09a934..b617bcdec 100644
--- a/test/test_build_powerplants.py
+++ b/test/test_build_powerplants.py
@@ -8,11 +8,12 @@
 Tests the functionalities of scripts/build_powerplants.py.
 """
 
+import pathlib
+import sys
+
 import numpy as np
 import pandas as pd
-import pathlib
 import pytest
-import sys
 
 sys.path.append("./scripts")