diff --git a/tests/integration/conftest.py b/tests/integration/conftest.py
index b396387..0235de2 100644
--- a/tests/integration/conftest.py
+++ b/tests/integration/conftest.py
@@ -116,10 +116,9 @@ async def jenkins_server_fixture(jenkins_server_model: Model) -> Application:
 async def server_unit_ip_fixture(jenkins_server_model: Model, jenkins_server: Application):
     """Get Jenkins machine server charm unit IP."""
     status: FullStatus = await jenkins_server_model.get_status([jenkins_server.name])
+    jenkins_application = typing.cast(Application, status.applications[jenkins_server.name])
     try:
-        unit_status: UnitStatus = next(
-            iter(status.applications[jenkins_server.name].units.values())
-        )
+        unit_status: UnitStatus = next(iter(jenkins_application.units.values()))
         assert unit_status.address, "Invalid unit address"
         return unit_status.address
     except StopIteration as exc:
diff --git a/tox.ini b/tox.ini
index cfd5fc0..9af1971 100644
--- a/tox.ini
+++ b/tox.ini
@@ -36,9 +36,9 @@ description = Check code against coding style standards
 deps =
     black
     codespell
-    flake8<6.0.0
+    flake8
     flake8-builtins
-    flake8-copyright<6.0.0
+    flake8-copyright
     flake8-docstrings>=1.6.0
     flake8-docstrings-complete>=1.0.3
     flake8-test-docs>=1.0
@@ -47,7 +47,7 @@ deps =
     pep8-naming
     pydocstyle>=2.10
     pylint
-    pyproject-flake8<6.0.0
+    pyproject-flake8
     pytest
     pytest-asyncio
     pytest-operator