diff --git a/src/charm.py b/src/charm.py
index e01dcedc..3ee19aec 100755
--- a/src/charm.py
+++ b/src/charm.py
@@ -44,7 +44,7 @@ def _on_config_changed(self, _event: ops.ConfigChangedEvent):
         Learn more about config at https://juju.is/docs/sdk/config
 
         Args:
-            event: event triggering the handler.
+            _event: event triggering the handler.
         """
         # Fetch an invalid config name
         self.model.config["log-level"].lower()
diff --git a/tests/unit/test_base.py b/tests/unit/test_base.py
index 73acc838..f6acc1a0 100644
--- a/tests/unit/test_base.py
+++ b/tests/unit/test_base.py
@@ -10,6 +10,7 @@
 import ops
 import ops.testing
 import pytest
+
 from charm import K8sCharm
 
 
diff --git a/tox.ini b/tox.ini
index ec6f826b..a742a523 100644
--- a/tox.ini
+++ b/tox.ini
@@ -26,20 +26,27 @@ passenv =
 description = Apply coding style standards to code
 deps =
     black
-    ruff
+    isort
 commands =
+    isort {[vars]all_path}
     black {[vars]all_path}
-    ruff {[vars]all_path} --fix
 
 [testenv:lint]
 description = Check code against coding style standards
 deps =
     black
     codespell
-    ruff
+    flake8<6.0.0
+    flake8-builtins
+    flake8-copyright<6.0.0
+    flake8-docstrings>=1.6.0
+    flake8-docstrings-complete>=1.0.3
+    flake8-test-docs>=1.0
     mypy
     pep8-naming
+    pydocstyle>=2.10
     pylint
+    pyproject-flake8<6.0.0
     pytest
     pytest-asyncio
     pytest-operator
@@ -53,7 +60,9 @@ commands =
     codespell {toxinidir} --skip {toxinidir}/.git --skip {toxinidir}/.tox \
       --skip {toxinidir}/build --skip {toxinidir}/lib --skip {toxinidir}/venv \
       --skip {toxinidir}/.mypy_cache --skip {toxinidir}/icon.svg
-    ruff {[vars]all_path}
+    # pflake8 wrapper supports config from pyproject.toml
+    pflake8 {[vars]all_path} --ignore=W503
+    isort --check-only --diff {[vars]all_path}
     black --check --diff {[vars]all_path}
     mypy {[vars]all_path}
     pylint {[vars]all_path}