diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 78e433a..f102fc2 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -3,7 +3,7 @@ default_language_version:
 
 repos:
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: "v0.15.22"
+    rev: "v0.16.0"
     hooks:
       - id: ruff
         args: ["--fix"]
diff --git a/docs/source/conf.py b/docs/source/conf.py
index 6413b4b..f68a225 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -18,7 +18,7 @@
 
 sys.path.insert(0, os.path.abspath("../../src"))
 
-from pytest_order import __version__  # noqa: E402
+from pytest_order import __version__
 
 # -- General configuration ------------------------------------------------
 
diff --git a/perf_tests/test_dependencies.py b/perf_tests/test_dependencies.py
index 37dd527..98d7931 100644
--- a/perf_tests/test_dependencies.py
+++ b/perf_tests/test_dependencies.py
@@ -1,7 +1,8 @@
-from unittest import mock
 from textwrap import dedent
+from unittest import mock
 
 import pytest
+
 from perf_tests.util import TimedSorter
 
 pytest_plugins = ["pytester"]
diff --git a/perf_tests/test_ordinal.py b/perf_tests/test_ordinal.py
index a269bb2..98253b2 100644
--- a/perf_tests/test_ordinal.py
+++ b/perf_tests/test_ordinal.py
@@ -1,7 +1,8 @@
-from unittest import mock
 from textwrap import dedent
+from unittest import mock
 
 import pytest
+
 from perf_tests.util import TimedSorter
 
 pytest_plugins = ["pytester"]
diff --git a/perf_tests/test_relative.py b/perf_tests/test_relative.py
index f70e3dd..229fe70 100644
--- a/perf_tests/test_relative.py
+++ b/perf_tests/test_relative.py
@@ -1,7 +1,8 @@
-from unittest import mock
 from textwrap import dedent
+from unittest import mock
 
 import pytest
+
 from perf_tests.util import TimedSorter
 
 pytest_plugins = ["pytester"]
diff --git a/perf_tests/test_relative_dense.py b/perf_tests/test_relative_dense.py
index 54158b0..a3a05e3 100644
--- a/perf_tests/test_relative_dense.py
+++ b/perf_tests/test_relative_dense.py
@@ -1,7 +1,8 @@
-from unittest import mock
 from textwrap import dedent
+from unittest import mock
 
 import pytest
+
 from perf_tests.util import TimedSorter
 
 pytest_plugins = ["pytester"]
diff --git a/src/pytest_order/item.py b/src/pytest_order/item.py
index 7c6be64..b14a898 100644
--- a/src/pytest_order/item.py
+++ b/src/pytest_order/item.py
@@ -1,12 +1,13 @@
+from __future__ import annotations
+
 import sys
-from typing import Optional, Generic, TypeVar
 from collections import defaultdict
+from typing import Generic, TypeVar
 
 from pytest import Function, UsageError
 
 from .settings import Scope, Settings
 
-
 _ItemType = TypeVar("_ItemType", "Item", "ItemGroup")
 
 
@@ -16,8 +17,8 @@ class Item:
     def __init__(self, item: Function, collection_index: int = 0) -> None:
         self.item: Function = item
         self.nr_rel_items: int = 0
-        self.order: Optional[int] = None
-        self._node_id: Optional[str] = None
+        self.order: int | None = None
+        self._node_id: str | None = None
         self.collection_index: int = collection_index
 
     def inc_rel_marks(self) -> None:
@@ -51,8 +52,8 @@ def __init__(
         items: list[Item],
         settings: Settings,
         scope: Scope,
-        rel_marks: list["RelativeMark[Item]"],
-        dep_marks: list["RelativeMark[Item]"],
+        rel_marks: list[RelativeMark[Item]],
+        dep_marks: list[RelativeMark[Item]],
     ) -> None:
         self.items = items
         self.settings = settings
@@ -160,9 +161,9 @@ def handle_dep_marks(self, sorted_list: list[Item]) -> None:
 
     @staticmethod
     def handle_relative_marks(
-        marks: list["RelativeMark[Item]"],
+        marks: list[RelativeMark[Item]],
         sorted_list: list[Item],
-        all_marks: list["RelativeMark[Item]"],
+        all_marks: list[RelativeMark[Item]],
     ) -> None:
         for mark in reversed(marks):
             if move_item(mark, sorted_list):
@@ -189,7 +190,7 @@ def print_unhandled_items(self) -> None:
             for item in failed_items:
                 item.item.fixturenames.insert(0, "fail_after_cannot_order")
 
-    def group_order(self) -> Optional[int]:
+    def group_order(self) -> int | None:
         if self.start_items:
             return self.start_items[0][0]
         elif self.end_items:
@@ -198,10 +199,10 @@ def group_order(self) -> Optional[int]:
 
     def _sort_by_topology(
         self,
-        items: list["Item"],
-        rel_marks: list["RelativeMark[Item]"],
-        dep_marks: list["RelativeMark[Item]"],
-    ) -> tuple[list["Item"], bool]:
+        items: list[Item],
+        rel_marks: list[RelativeMark[Item]],
+        dep_marks: list[RelativeMark[Item]],
+    ) -> tuple[list[Item], bool]:
         """
         Order items so that all relative constraints are satisfied while staying as
         close as possible to the incoming order (the absolute-ordinal baseline).
@@ -261,7 +262,7 @@ class ItemGroup:
     """
 
     def __init__(
-        self, items: Optional[list[Item]] = None, order: Optional[int] = None
+        self, items: list[Item] | None = None, order: int | None = None
     ) -> None:
         self.items: list[Item] = items or []
         self.order = order
@@ -275,7 +276,7 @@ def dec_rel_marks(self) -> None:
         if self.order is None:
             self.nr_rel_items -= 1
 
-    def extend(self, groups: list["ItemGroup"], order: Optional[int]) -> None:
+    def extend(self, groups: list[ItemGroup], order: int | None) -> None:
         for group in groups:
             self.items.extend(group.items)
         self.order = order
@@ -339,9 +340,9 @@ def move_item(mark: RelativeMark[_ItemType], sorted_items: list[_ItemType]) -> b
 
 
 def _build_predecessors(
-    marks: list["RelativeMark[Item]"],
-    item_set: set["Item"],
-) -> "defaultdict[Item, list[Item]]":
+    marks: list[RelativeMark[Item]],
+    item_set: set[Item],
+) -> defaultdict[Item, list[Item]]:
     """Map each item to the items that must run before it, derived from the
     relative marks. A mark either places item_to_move after item (move_after)
     or before it."""
diff --git a/src/pytest_order/plugin.py b/src/pytest_order/plugin.py
index ce0a618..8348df1 100644
--- a/src/pytest_order/plugin.py
+++ b/src/pytest_order/plugin.py
@@ -1,11 +1,11 @@
-from collections.abc import Generator, Callable
+from collections.abc import Callable, Generator
 
 import pytest
-from pytest import Function
 from _pytest.config import Config
 from _pytest.config.argparsing import Parser
 from _pytest.main import Session
 from _pytest.mark import Mark
+from pytest import Function
 
 from .sorter import Sorter
 
@@ -157,24 +157,25 @@ def pytest_generate_tests(metafunc):
 
     Make parametrized tests with corresponding order marks.
     """
-    if getattr(metafunc, "function", False):
-        if getattr(metafunc.function, "pytestmark", False):
-            # Get list of order marks
-            marks = metafunc.function.pytestmark
-            order_marks = [mark for mark in marks if mark.name == "order"]
-            if len(order_marks) > 1:
-                # Remove all order marks
-                metafunc.function.pytestmark = [
-                    mark for mark in marks if mark.name != "order"
-                ]
-                # Prepare arguments for parametrization with order marks
-                args = [
-                    pytest.param(_get_mark_description(mark), marks=[mark])
-                    for mark in order_marks
-                ]
-                if "order" not in metafunc.fixturenames:
-                    metafunc.fixturenames.append("order")
-                metafunc.parametrize("order", args)
+    if getattr(metafunc, "function", False) and getattr(
+        metafunc.function, "pytestmark", False
+    ):
+        # Get list of order marks
+        marks = metafunc.function.pytestmark
+        order_marks = [mark for mark in marks if mark.name == "order"]
+        if len(order_marks) > 1:
+            # Remove all order marks
+            metafunc.function.pytestmark = [
+                mark for mark in marks if mark.name != "order"
+            ]
+            # Prepare arguments for parametrization with order marks
+            args = [
+                pytest.param(_get_mark_description(mark), marks=[mark])
+                for mark in order_marks
+            ]
+            if "order" not in metafunc.fixturenames:
+                metafunc.fixturenames.append("order")
+            metafunc.parametrize("order", args)
 
 
 @pytest.fixture
diff --git a/src/pytest_order/settings.py b/src/pytest_order/settings.py
index fe4c5ea..1b796ec 100644
--- a/src/pytest_order/settings.py
+++ b/src/pytest_order/settings.py
@@ -1,4 +1,5 @@
 from enum import Enum
+from typing import ClassVar
 from warnings import warn
 
 from _pytest.config import Config
@@ -13,7 +14,7 @@ class Scope(Enum):
 class Settings:
     """Holds all configuration settings."""
 
-    valid_scopes = {
+    valid_scopes: ClassVar = {
         "class": Scope.CLASS,
         "module": Scope.MODULE,
         "session": Scope.SESSION,
diff --git a/src/pytest_order/sorter.py b/src/pytest_order/sorter.py
index f4aac11..eca7b57 100644
--- a/src/pytest_order/sorter.py
+++ b/src/pytest_order/sorter.py
@@ -1,16 +1,18 @@
+from __future__ import annotations
+
 import re
 import sys
 from collections import OrderedDict
 from contextlib import suppress
-from typing import Optional, cast
+from typing import cast
 from warnings import warn
 
 from _pytest.config import Config
 from _pytest.mark import Mark
 from pytest import Function, UsageError
 
-from .item import Item, ItemList, ItemGroup, filter_marks, move_item, RelativeMark
-from .settings import Settings, Scope
+from .item import Item, ItemGroup, ItemList, RelativeMark, filter_marks, move_item
+from .settings import Scope, Settings
 
 orders_map = {
     "first": 0,
@@ -298,7 +300,7 @@ def resolve_dependency_markers(
                     alias = self.matching_alias(aliases[name], item)
                     self.dep_marks.append(RelativeMark(alias, item, move_after=True))
             else:
-                label = "::".join((prefix, name))
+                label = f"{prefix}::{name}"
                 if label in aliases:
                     for item in items:
                         alias = self.matching_alias(aliases[label], item)
@@ -512,13 +514,13 @@ def collect_group_marks(
                 group_to_move.inc_rel_marks()
         return group_marks
 
-    def group_for_item(self, item: Item) -> Optional[ItemGroup]:
+    def group_for_item(self, item: Item) -> ItemGroup | None:
         for group in self.groups:
             if item in group.items:
                 return group
         return None
 
-    def sorted_groups(self) -> tuple[Optional[int], list[ItemGroup]]:
+    def sorted_groups(self) -> tuple[int | None, list[ItemGroup]]:
         group_order = self.sort_by_ordinal_markers()
         length = len(self.rel_marks) + len(self.dep_marks)
         if length == 0:
@@ -532,7 +534,7 @@ def sorted_groups(self) -> tuple[Optional[int], list[ItemGroup]]:
             self.handle_rel_marks(self.dep_marks)
         return group_order, self.groups
 
-    def sort_by_ordinal_markers(self) -> Optional[int]:
+    def sort_by_ordinal_markers(self) -> int | None:
         start_groups = []
         middle_groups = []
         end_groups = []
diff --git a/tests/test_class_marks.py b/tests/test_class_marks.py
index 3edfead..61ca60d 100644
--- a/tests/test_class_marks.py
+++ b/tests/test_class_marks.py
@@ -61,7 +61,7 @@ def test_2(self): pass
         "Test2::test_1",
         "Test2::test_2",
     ]
-    out, err = capsys.readouterr()
+    out, _ = capsys.readouterr()
     assert (
         "WARNING: cannot execute 'test_2' relative to others: "
         "'Test3' - ignoring the marker" in out
diff --git a/tests/test_dependency.py b/tests/test_dependency.py
index 7d30a95..34b2f2d 100644
--- a/tests/test_dependency.py
+++ b/tests/test_dependency.py
@@ -262,7 +262,7 @@ def test_c(self):
         "Test::test_b",
         "Test::test_c",
     ]
-    out, err = capsys.readouterr()
+    out, _ = capsys.readouterr()
     warning = "Cannot resolve the dependency marker 'test_c' - ignoring it"
     assert warning in out
 
@@ -565,7 +565,7 @@ def test_c(self):
         "Test::test_b",
         "Test::test_c",
     ]
-    out, err = capsys.readouterr()
+    out, _ = capsys.readouterr()
     warning = "Cannot resolve the dependency marker 'test_3' - ignoring it."
     assert warning in out
 
diff --git a/tests/test_misc.py b/tests/test_misc.py
index 0480bfa..077103b 100644
--- a/tests/test_misc.py
+++ b/tests/test_misc.py
@@ -19,7 +19,7 @@ def test_version_valid():
 
 def test_markers_registered(capsys):
     pytest.main(["--markers"])
-    out, err = capsys.readouterr()
+    out, _ = capsys.readouterr()
     assert "@pytest.mark.order" in out
     # only order is supported as marker
     assert out.count("Provided by pytest-order.") == 1
diff --git a/tests/test_order_scope_level.py b/tests/test_order_scope_level.py
index 624811b..57bb166 100644
--- a/tests/test_order_scope_level.py
+++ b/tests/test_order_scope_level.py
@@ -135,7 +135,9 @@ def test_invalid_scope(fixture_path):
     result.assert_outcomes(passed=12, failed=0)
     result.stdout.fnmatch_lines(
         [
-            "*UserWarning: order-scope-level cannot be used "
-            "together with --order-scope=module*"
+            (
+                "*UserWarning: order-scope-level cannot be used "
+                "together with --order-scope=module*"
+            )
         ]
     )
diff --git a/tests/test_relative_ordering.py b/tests/test_relative_ordering.py
index 3758717..7c5325a 100644
--- a/tests/test_relative_ordering.py
+++ b/tests/test_relative_ordering.py
@@ -414,7 +414,7 @@ def test_2():
             pass
         """
     assert item_names_for(test_content) == ["test_1", "test_2"]
-    out, err = capsys.readouterr()
+    out, _ = capsys.readouterr()
     warning = (
         "cannot execute 'test_1' relative to others: 'some_module.py::test_2' "
         "- ignoring the marker"
@@ -437,7 +437,7 @@ def test_3():
             pass
         """
     assert item_names_for(test_content) == ["test_1", "test_2", "test_3"]
-    out, err = capsys.readouterr()
+    out, _ = capsys.readouterr()
     warning = (
         "cannot execute 'test_2' relative to others: 'test_4' - ignoring the marker"
     )
@@ -518,7 +518,7 @@ def test_3(self):
         "Test::test_2",
         "Test::test_3",
     ]
-    out, err = capsys.readouterr()
+    out, _ = capsys.readouterr()
     warning = (
         "cannot execute 'test_2' relative to others: 'test_4' - ignoring the marker"
     )
@@ -546,7 +546,7 @@ def test_3():
     # test_3 and test_1 are topologically sorted: test_3 → test_1
     assert item_names_for(test_content) == ["test_2", "test_3", "test_1"]
     # No warning should be issued since the constraints are consistent
-    out, err = capsys.readouterr()
+    out, _ = capsys.readouterr()
     assert "cannot execute test relative to others" not in out
 
 
@@ -612,8 +612,10 @@ def test_3():
     result.assert_outcomes(passed=0, failed=0)
     result.stderr.fnmatch_lines(
         [
-            "ERROR: pytest-order: cannot execute test relative to others: "
-            "test_failed_ordering.py::test_* test_failed_ordering.py::test_*"
+            (
+                "ERROR: pytest-order: cannot execute test relative to others: "
+                "test_failed_ordering.py::test_* test_failed_ordering.py::test_*"
+            )
         ]
     )
 
diff --git a/tests/test_xdist_handling.py b/tests/test_xdist_handling.py
index 0ac6f2c..fb61e9b 100644
--- a/tests/test_xdist_handling.py
+++ b/tests/test_xdist_handling.py
@@ -1,6 +1,7 @@
 from textwrap import dedent
 
 import pytest
+
 import pytest_order