diff --git a/harmonizer/main.py b/harmonizer/main.py
index 3266f59..9479494 100644
--- a/harmonizer/main.py
+++ b/harmonizer/main.py
@@ -84,9 +84,7 @@ def load_configuration() -> Dict:
                         return config
                     return {}
             except (yaml.YAMLError, IOError) as e:
-                print(
-                    f"WARNING: Could not load or parse config: {e}", file=sys.stderr
-                )
+                print(f"WARNING: Could not load or parse config: {e}", file=sys.stderr)
                 return {}
 
         parent_dir = os.path.dirname(current_dir)
diff --git a/tests/conftest.py b/tests/conftest.py
index dd472ab..c6c9345 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -6,5 +6,5 @@
 # Add the project root to the Python path.
 # This ensures that the 'harmonizer' package is discoverable by pytest,
 # regardless of how the project is installed or the current working directory.
-project_root = os.path.abspath(os.path.join(os.path.dirname(__file__), '..'))
+project_root = os.path.abspath(os.path.join(os.path.dirname(__file__), ".."))
 sys.path.insert(0, project_root)
diff --git a/tests/test_harmonizer.py b/tests/test_harmonizer.py
index 5e359a9..e1a4195 100644
--- a/tests/test_harmonizer.py
+++ b/tests/test_harmonizer.py
@@ -5,7 +5,11 @@
 import argparse
 import pytest
 
-from harmonizer.main import PythonCodeHarmonizer, load_configuration, validate_cli_arguments
+from harmonizer.main import (
+    PythonCodeHarmonizer,
+    load_configuration,
+    validate_cli_arguments,
+)
 
 # A self-contained Python script to be used for testing.
 # It contains one harmonious function and one disharmonious one.