diff --git a/setup.cfg b/setup.cfg
index 666f2e62..5b6de398 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -2,7 +2,8 @@
 max-line-length = 100
 extend-ignore = E203, E501
 ban-relative-imports = parents
-per-file-ignores = __init__.py:F401,F403,E402
+per-file-ignores =
+    __init__.py:F401,F403,E402
 ;exclude = *.py
 
 [black]
diff --git a/tests/test_visualization.py b/tests/test_visualization.py
index 526e6d42..17886ca5 100644
--- a/tests/test_visualization.py
+++ b/tests/test_visualization.py
@@ -2,7 +2,8 @@
 from pytest_cases import parametrize_with_cases
 from pytest import raises
 
-import gval
+# added comment because of flake8 believes it's unused
+import gval  # noqa: F401
 
 
 @parametrize_with_cases(