diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 7a056a1a5..d278c2598 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -20,12 +20,12 @@ jobs:
       # do not abort the whole test job if one combination in the matrix fails
       fail-fast: false
       matrix:
-        python-version: ["3.8", "3.12"]
+        python-version: ["3.9", "3.12"]
         os: [ubuntu-22.04]
         include:
-          - python-version: "3.8"
+          - python-version: "3.9"
             os: macos-latest
-          - python-version: "3.8"
+          - python-version: "3.9"
             os: windows-latest
 
     steps:
@@ -49,7 +49,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v2
         with:
-          python-version: 3.8
+          python-version: 3.9
       - name: Install dependencies
         run: |
           pip install poetry~=1.3.0
@@ -65,7 +65,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v2
         with:
-          python-version: 3.8
+          python-version: 3.9
       - name: Install dependencies
         run: |
           pip install poetry~=1.3.0
@@ -82,7 +82,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v2
         with:
-          python-version: 3.8
+          python-version: 3.9
       - name: Install dependencies
         run: |
           pip install poetry~=1.3.0
@@ -108,7 +108,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v2
         with:
-          python-version: 3.8
+          python-version: 3.9
       - name: Install dependencies
         run: |
           pip install poetry~=1.3.0
@@ -123,7 +123,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v2
         with:
-          python-version: 3.8
+          python-version: 3.9
       - name: Install dependencies
         run: |
           pip install poetry~=1.3.0
diff --git a/.github/workflows/third_party_lint.yaml b/.github/workflows/third_party_lint.yaml
index 98abad12b..ed2a7c33c 100644
--- a/.github/workflows/third_party_lint.yaml
+++ b/.github/workflows/third_party_lint.yaml
@@ -33,7 +33,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v2
         with:
-          python-version: 3.8
+          python-version: 3.9
       - name: Install dependencies
         run: |
           pip install poetry~=1.3.0
@@ -56,7 +56,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v2
         with:
-          python-version: 3.8
+          python-version: 3.9
       - name: Install dependencies
         run: |
           pip install poetry~=1.3.0
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index d43bc7d3d..d9a1eb19d 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -8,7 +8,7 @@ build:
   # This should mirror the configuration in ./.github/workflows/test.yaml
   os: ubuntu-22.04
   tools:
-    python: "3.8"
+    python: "3.9"
   jobs:
     post_create_environment:
       - python -m pip install poetry
diff --git a/README.md b/README.md
index 66107ce92..151675b81 100644
--- a/README.md
+++ b/README.md
@@ -20,7 +20,7 @@ recommendations.
 - Source code: <https://github.com/fsfe/reuse-tool>
 - PyPI: <https://pypi.python.org/pypi/reuse>
 - REUSE: 3.3
-- Python: 3.8+
+- Python: 3.9+
 
 ## Table of contents
 
diff --git a/changelog.d/removed/python-3.8.md b/changelog.d/removed/python-3.8.md
new file mode 100644
index 000000000..46bc7c986
--- /dev/null
+++ b/changelog.d/removed/python-3.8.md
@@ -0,0 +1 @@
+- Python 3.8 support removed. (#1080)
diff --git a/poetry.lock b/poetry.lock
index 728d880a5..f111b82d3 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -59,9 +59,6 @@ files = [
     {file = "babel-2.15.0.tar.gz", hash = "sha256:8daf0e265d05768bc6c7a314cf1321e9a123afc328cc635c18622a2f30a04413"},
 ]
 
-[package.dependencies]
-pytz = {version = ">=2015.7", markers = "python_version < \"3.9\""}
-
 [package.extras]
 dev = ["freezegun (>=1.0,<2.0)", "pytest (>=6.0)", "pytest-cov"]
 
@@ -1312,18 +1309,6 @@ test = ["coverage", "flaky", "matplotlib", "numpy", "pandas", "pylint (>=3.1,<4)
 websockets = ["websockets (>=10.3)"]
 yapf = ["whatthepatch (>=1.0.2,<2.0.0)", "yapf (>=0.33.0)"]
 
-[[package]]
-name = "pytz"
-version = "2024.1"
-description = "World timezone definitions, modern and historical"
-category = "dev"
-optional = false
-python-versions = "*"
-files = [
-    {file = "pytz-2024.1-py2.py3-none-any.whl", hash = "sha256:328171f4e3623139da4983451950b28e95ac706e13f3f2630a879749e7a8b319"},
-    {file = "pytz-2024.1.tar.gz", hash = "sha256:2a29735ea9c18baf14b448846bde5a48030ed267578472d8955cd0e7443a9812"},
-]
-
 [[package]]
 name = "pyyaml"
 version = "6.0.1"
@@ -1350,6 +1335,7 @@ files = [
     {file = "PyYAML-6.0.1-cp311-cp311-win_amd64.whl", hash = "sha256:bf07ee2fef7014951eeb99f56f39c9bb4af143d8aa3c21b1677805985307da34"},
     {file = "PyYAML-6.0.1-cp312-cp312-macosx_10_9_x86_64.whl", hash = "sha256:855fb52b0dc35af121542a76b9a84f8d1cd886ea97c84703eaa6d88e37a2ad28"},
     {file = "PyYAML-6.0.1-cp312-cp312-macosx_11_0_arm64.whl", hash = "sha256:40df9b996c2b73138957fe23a16a4f0ba614f4c0efce1e9406a184b6d07fa3a9"},
+    {file = "PyYAML-6.0.1-cp312-cp312-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:a08c6f0fe150303c1c6b71ebcd7213c2858041a7e01975da3a99aed1e7a378ef"},
     {file = "PyYAML-6.0.1-cp312-cp312-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:6c22bec3fbe2524cde73d7ada88f6566758a8f7227bfbf93a408a9d86bcc12a0"},
     {file = "PyYAML-6.0.1-cp312-cp312-musllinux_1_1_x86_64.whl", hash = "sha256:8d4e9c88387b0f5c7d5f281e55304de64cf7f9c0021a3525bd3b1c542da3b0e4"},
     {file = "PyYAML-6.0.1-cp312-cp312-win32.whl", hash = "sha256:d483d2cdf104e7c9fa60c544d92981f12ad66a457afae824d146093b8c294c54"},
@@ -1812,5 +1798,5 @@ test = ["big-O", "importlib-resources", "jaraco.functools", "jaraco.itertools",
 
 [metadata]
 lock-version = "2.0"
-python-versions = "^3.8"
-content-hash = "3f000ef7f191dd1e5648641ddfef4e469429e33e583299bbcac630bfd59ac10b"
+python-versions = "^3.9"
+content-hash = "be47ee3f7fe85c83152cadb5b1755beb125dc2766f19a10615c4eeae02d2349b"
diff --git a/pyproject.toml b/pyproject.toml
index 1f8e51d87..7c99550e1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -52,12 +52,14 @@ classifiers = [
 ]
 
 [tool.poetry.dependencies]
-python = "^3.8"
+python = "^3.9"
 Jinja2 = ">=3.0.0"
 binaryornot = ">=0.4.4"
 "boolean.py" = ">=3.8"
 license-expression = ">=1.0"
 python-debian = ">=0.1.34,!=0.1.45,!=0.1.46,!=0.1.47"
+# TODO: Consider removing this dependency in favour of tomllib when dropping
+# Python 3.10.
 tomlkit = ">=0.8"
 attrs = ">=21.3"
 
diff --git a/src/reuse/__init__.py b/src/reuse/__init__.py
index bc7474199..495f35ed6 100644
--- a/src/reuse/__init__.py
+++ b/src/reuse/__init__.py
@@ -16,6 +16,9 @@
 change the public API.
 """
 
+# TODO: When Python 3.9 is dropped, consider using `type | None` instead of
+# `Optional[type]`.
+
 import gettext
 import logging
 import os
@@ -23,7 +26,7 @@
 from dataclasses import dataclass, field
 from enum import Enum
 from importlib.metadata import PackageNotFoundError, version
-from typing import Any, Dict, NamedTuple, Optional, Set, Type
+from typing import Any, Optional
 
 from boolean.boolean import Expression
 
@@ -108,9 +111,9 @@ class SourceType(Enum):
 class ReuseInfo:
     """Simple dataclass holding licensing and copyright information"""
 
-    spdx_expressions: Set[Expression] = field(default_factory=set)
-    copyright_lines: Set[str] = field(default_factory=set)
-    contributor_lines: Set[str] = field(default_factory=set)
+    spdx_expressions: set[Expression] = field(default_factory=set)
+    copyright_lines: set[str] = field(default_factory=set)
+    contributor_lines: set[str] = field(default_factory=set)
     path: Optional[str] = None
     source_path: Optional[str] = None
     source_type: Optional[SourceType] = None
@@ -134,10 +137,10 @@ def copy(self, **kwargs: Any) -> "ReuseInfo":
         return self.__class__(**new_kwargs)  # type: ignore
 
     def union(self, value: "ReuseInfo") -> "ReuseInfo":
-        """Return a new instance of ReuseInfo where all Set attributes are equal
+        """Return a new instance of ReuseInfo where all set attributes are equal
         to the union of the set in *self* and the set in *value*.
 
-        All non-Set attributes are set to their values in *self*.
+        All non-set attributes are set to their values in *self*.
 
         >>> one = ReuseInfo(copyright_lines={"Jane Doe"}, source_path="foo.py")
         >>> two = ReuseInfo(copyright_lines={"John Doe"}, source_path="bar.py")
diff --git a/src/reuse/_annotate.py b/src/reuse/_annotate.py
index c45918554..40daec635 100644
--- a/src/reuse/_annotate.py
+++ b/src/reuse/_annotate.py
@@ -22,7 +22,7 @@
 from argparse import SUPPRESS, ArgumentParser, Namespace
 from gettext import gettext as _
 from pathlib import Path
-from typing import IO, Iterable, Optional, Set, Tuple, Type, cast
+from typing import IO, Iterable, Optional, Type, cast
 
 from binaryornot.check import is_binary
 from jinja2 import Environment, FileSystemLoader, Template
@@ -232,13 +232,13 @@ def test_mandatory_option_required(args: Namespace) -> None:
         )
 
 
-def all_paths(args: Namespace, project: Project) -> Set[Path]:
+def all_paths(args: Namespace, project: Project) -> set[Path]:
     """Return a set of all provided paths, converted into .license paths if they
     exist. If recursive is enabled, all files belonging to *project* are also
     added.
     """
     if args.recursive:
-        paths: Set[Path] = set()
+        paths: set[Path] = set()
         all_files = [path.resolve() for path in project.all_files()]
         for path in args.path:
             if path.is_file():
@@ -256,7 +256,7 @@ def all_paths(args: Namespace, project: Project) -> Set[Path]:
 
 def get_template(
     args: Namespace, project: Project
-) -> Tuple[Optional[Template], bool]:
+) -> tuple[Optional[Template], bool]:
     """If a template is specified on the CLI, find and return it, including
     whether it is a 'commented' template.
 
diff --git a/src/reuse/_licenses.py b/src/reuse/_licenses.py
index 76ffc3827..e3c947b0f 100644
--- a/src/reuse/_licenses.py
+++ b/src/reuse/_licenses.py
@@ -11,7 +11,6 @@
 
 import json
 import os
-from typing import Dict, List, Tuple
 
 _BASE_DIR = os.path.dirname(__file__)
 _RESOURCES_DIR = os.path.join(_BASE_DIR, "resources")
@@ -19,7 +18,7 @@
 _EXCEPTIONS = os.path.join(_RESOURCES_DIR, "exceptions.json")
 
 
-def _load_license_list(file_name: str) -> Tuple[List[int], Dict[str, Dict]]:
+def _load_license_list(file_name: str) -> tuple[list[int], dict[str, dict]]:
     """Return the licenses list version tuple and a mapping of licenses
     id->name loaded from a JSON file
     from https://github.com/spdx/license-list-data
@@ -34,7 +33,7 @@ def _load_license_list(file_name: str) -> Tuple[List[int], Dict[str, Dict]]:
     return version, licenses_map
 
 
-def _load_exception_list(file_name: str) -> Tuple[List[int], Dict[str, Dict]]:
+def _load_exception_list(file_name: str) -> tuple[list[int], dict[str, dict]]:
     """Return the exceptions list version tuple and a mapping of
     exceptions id->name loaded from a JSON file
     from https://github.com/spdx/license-list-data
diff --git a/src/reuse/_lint_file.py b/src/reuse/_lint_file.py
index 39e5cd469..2c8d53eb3 100644
--- a/src/reuse/_lint_file.py
+++ b/src/reuse/_lint_file.py
@@ -12,7 +12,7 @@
 from pathlib import Path
 from typing import IO
 
-from ._util import PathType, is_relative_to
+from ._util import PathType
 from .lint import format_lines_subset
 from .project import Project
 from .report import ProjectSubsetReport
@@ -43,7 +43,7 @@ def run(args: Namespace, project: Project, out: IO[str] = sys.stdout) -> int:
     """List all non-compliant files from specified file list."""
     subset_files = {Path(file_) for file_ in args.files}
     for file_ in subset_files:
-        if not is_relative_to(file_.resolve(), project.root.resolve()):
+        if not file_.resolve().is_relative_to(project.root.resolve()):
             args.parser.error(
                 _("'{file}' is not inside of '{root}'").format(
                     file=file_, root=project.root
diff --git a/src/reuse/_main.py b/src/reuse/_main.py
index b5df4a7f7..d395f302d 100644
--- a/src/reuse/_main.py
+++ b/src/reuse/_main.py
@@ -15,7 +15,7 @@
 import warnings
 from gettext import gettext as _
 from pathlib import Path
-from typing import IO, Callable, List, Optional, Type, cast
+from typing import IO, Callable, Optional, Type, cast
 
 from . import (
     __REUSE_version__,
@@ -219,7 +219,7 @@ def add_command(  # pylint: disable=too-many-arguments,redefined-builtin
     formatter_class: Optional[Type[argparse.HelpFormatter]] = None,
     description: Optional[str] = None,
     help: Optional[str] = None,
-    aliases: Optional[List[str]] = None,
+    aliases: Optional[list[str]] = None,
 ) -> None:
     """Add a subparser for a command."""
     if formatter_class is None:
@@ -236,10 +236,10 @@ def add_command(  # pylint: disable=too-many-arguments,redefined-builtin
     subparser.set_defaults(parser=subparser)
 
 
-def main(args: Optional[List[str]] = None, out: IO[str] = sys.stdout) -> int:
+def main(args: Optional[list[str]] = None, out: IO[str] = sys.stdout) -> int:
     """Main entry function."""
     if args is None:
-        args = cast(List[str], sys.argv[1:])
+        args = cast(list[str], sys.argv[1:])
 
     main_parser = parser()
     parsed_args = main_parser.parse_args(args)
diff --git a/src/reuse/_util.py b/src/reuse/_util.py
index 58de0d1f3..c906dd64e 100644
--- a/src/reuse/_util.py
+++ b/src/reuse/_util.py
@@ -14,7 +14,6 @@
 
 """Misc. utilities for reuse."""
 
-import contextlib
 import logging
 import os
 import re
@@ -29,20 +28,8 @@
 from inspect import cleandoc
 from itertools import chain
 from os import PathLike
-from pathlib import Path, PurePath
-from typing import (
-    IO,
-    Any,
-    BinaryIO,
-    Dict,
-    Iterator,
-    List,
-    Optional,
-    Set,
-    Type,
-    Union,
-    cast,
-)
+from pathlib import Path
+from typing import IO, Any, BinaryIO, Iterator, Optional, Type, Union, cast
 
 from boolean.boolean import Expression, ParseError
 from license_expression import ExpressionError, Licensing
@@ -57,8 +44,7 @@
     _all_style_classes,
 )
 
-# TODO: When removing Python 3.8 support, use PathLike[str]
-StrPath = Union[str, PathLike]
+StrPath = Union[str, PathLike[str]]
 
 GIT_EXE = shutil.which("git")
 HG_EXE = shutil.which("hg")
@@ -109,7 +95,7 @@
     r"^(.*?)SPDX-FileContributor:[ \t]+(.*?)" + _END_PATTERN, re.MULTILINE
 )
 # The keys match the relevant attributes of ReuseInfo.
-_SPDX_TAGS: Dict[str, re.Pattern] = {
+_SPDX_TAGS: dict[str, re.Pattern] = {
     "spdx_expressions": _LICENSE_IDENTIFIER_PATTERN,
     "contributor_lines": _CONTRIBUTOR_PATTERN,
 }
@@ -171,7 +157,7 @@ def setup_logging(level: int = logging.WARNING) -> None:
 
 
 def execute_command(
-    command: List[str],
+    command: list[str],
     logger: logging.Logger,
     cwd: Optional[StrPath] = None,
     **kwargs: Any,
@@ -251,9 +237,9 @@ def _determine_license_suffix_path(path: StrPath) -> Path:
     return Path(f"{path}.license")
 
 
-def _parse_copyright_year(year: Optional[str]) -> List[str]:
+def _parse_copyright_year(year: Optional[str]) -> list[str]:
     """Parse copyright years and return list."""
-    ret: List[str] = []
+    ret: list[str] = []
     if not year:
         return ret
     if re.match(r"\d{4}$", year):
@@ -295,7 +281,7 @@ def _has_style(path: Path) -> bool:
     return _get_comment_style(path) is not None
 
 
-def merge_copyright_lines(copyright_lines: Set[str]) -> Set[str]:
+def merge_copyright_lines(copyright_lines: set[str]) -> set[str]:
     """Parse all copyright lines and merge identical statements making years
     into a range.
 
@@ -339,7 +325,7 @@ def merge_copyright_lines(copyright_lines: Set[str]) -> Set[str]:
                 break
 
         # get year range if any
-        years: List[str] = []
+        years: list[str] = []
         for copy in copyright_list:
             years += copy["year"]
 
@@ -362,7 +348,7 @@ def extract_reuse_info(text: str) -> ReuseInfo:
         ParseError: if an SPDX expression could not be parsed.
     """
     text = filter_ignore_block(text)
-    spdx_tags: Dict[str, Set[str]] = {}
+    spdx_tags: dict[str, set[str]] = {}
     for tag, pattern in _SPDX_TAGS.items():
         spdx_tags[tag] = set(find_spdx_tag(text, pattern))
     # License expressions and copyright matches are special cases.
@@ -605,9 +591,9 @@ def spdx_identifier(text: str) -> Expression:
         ) from error
 
 
-def similar_spdx_identifiers(identifier: str) -> List[str]:
+def similar_spdx_identifiers(identifier: str) -> list[str]:
     """Given an incorrect SPDX identifier, return a list of similar ones."""
-    suggestions: List[str] = []
+    suggestions: list[str] = []
     if identifier in ALL_NON_DEPRECATED_MAP:
         return suggestions
 
@@ -665,13 +651,4 @@ def cleandoc_nl(text: str) -> str:
     return cleandoc(text) + "\n"
 
 
-def is_relative_to(path: PurePath, target: PurePath) -> bool:
-    """Like Path.is_relative_to, but working for Python <3.9."""
-    # TODO: When Python 3.8 is dropped, remove this function.
-    with contextlib.suppress(ValueError):
-        path.relative_to(target)
-        return True
-    return False
-
-
 # REUSE-IgnoreEnd
diff --git a/src/reuse/comment.py b/src/reuse/comment.py
index ad7b4f2db..ac1253ab5 100644
--- a/src/reuse/comment.py
+++ b/src/reuse/comment.py
@@ -29,7 +29,7 @@
 import operator
 import re
 from textwrap import dedent
-from typing import List, NamedTuple, Optional, Type
+from typing import NamedTuple, Optional, Type
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -65,7 +65,7 @@ class CommentStyle:
     INDENT_BEFORE_MIDDLE = ""
     INDENT_AFTER_MIDDLE = ""
     INDENT_BEFORE_END = ""
-    SHEBANGS: List[str] = []
+    SHEBANGS: list[str] = []
 
     @classmethod
     def can_handle_single(cls) -> bool:
@@ -162,10 +162,9 @@ def _parse_comment_single(cls, text: str) -> str:
         result_lines = []
 
         for line in text.splitlines():
-            # TODO: When Python 3.8 is dropped, consider using str.removeprefix
             if cls.SINGLE_LINE_REGEXP:
                 if match := cls.SINGLE_LINE_REGEXP.match(line):
-                    line = line.lstrip(match.group(0))
+                    line = line.removeprefix(match.group(0))
                     result_lines.append(line)
                     continue
 
@@ -173,7 +172,7 @@ def _parse_comment_single(cls, text: str) -> str:
                 raise CommentParseError(
                     f"'{line}' does not start with a comment marker"
                 )
-            line = line.lstrip(cls.SINGLE_LINE)
+            line = line.removeprefix(cls.SINGLE_LINE)
             result_lines.append(line)
 
         result = "\n".join(result_lines)
@@ -909,7 +908,7 @@ class XQueryCommentStyle(CommentStyle):
 }
 
 
-def _all_style_classes() -> List[Type[CommentStyle]]:
+def _all_style_classes() -> list[Type[CommentStyle]]:
     """Return a list of all defined style classes, excluding the base class."""
     result = []
     for key, value in globals().items():
diff --git a/src/reuse/convert_dep5.py b/src/reuse/convert_dep5.py
index da6dca79f..b33a8b219 100644
--- a/src/reuse/convert_dep5.py
+++ b/src/reuse/convert_dep5.py
@@ -8,7 +8,7 @@
 import sys
 from argparse import ArgumentParser, Namespace
 from gettext import gettext as _
-from typing import IO, Any, Dict, Iterable, List, Optional, TypeVar, Union, cast
+from typing import IO, Any, Iterable, Optional, TypeVar, Union, cast
 
 import tomlkit
 from debian.copyright import Copyright, FilesParagraph, Header
@@ -23,8 +23,8 @@
 
 def _collapse_list_if_one_item(
     # Technically this should be Sequence[_T], but I can't get that to work.
-    sequence: List[_T],
-) -> Union[List[_T], _T]:
+    sequence: list[_T],
+) -> Union[list[_T], _T]:
     """Return the only item of the list if the length of the list is one, else
     return the list.
     """
@@ -35,8 +35,8 @@ def _collapse_list_if_one_item(
 
 def _header_from_dep5_header(
     header: Header,
-) -> Dict[str, Union[str, List[str]]]:
-    result: Dict[str, Union[str, List[str]]] = {}
+) -> dict[str, Union[str, list[str]]]:
+    result: dict[str, Union[str, list[str]]] = {}
     if header.upstream_name:
         result["SPDX-PackageName"] = str(header.upstream_name)
     if header.upstream_contact:
@@ -52,7 +52,7 @@ def _header_from_dep5_header(
 
 def _copyrights_from_paragraph(
     paragraph: FilesParagraph,
-) -> Union[str, List[str]]:
+) -> Union[str, list[str]]:
     return _collapse_list_if_one_item(
         [line.strip() for line in cast(str, paragraph.copyright).splitlines()]
     )
@@ -65,7 +65,7 @@ def _convert_asterisk(path: str) -> str:
     return _SINGLE_ASTERISK_PATTERN.sub("**", path)
 
 
-def _paths_from_paragraph(paragraph: FilesParagraph) -> Union[str, List[str]]:
+def _paths_from_paragraph(paragraph: FilesParagraph) -> Union[str, list[str]]:
     return _collapse_list_if_one_item(
         [_convert_asterisk(path) for path in list(paragraph.files)]
     )
@@ -77,7 +77,7 @@ def _comment_from_paragraph(paragraph: FilesParagraph) -> Optional[str]:
 
 def _annotations_from_paragraphs(
     paragraphs: Iterable[FilesParagraph],
-) -> List[Dict[str, Union[str, List[str]]]]:
+) -> list[dict[str, Union[str, list[str]]]]:
     annotations = []
     for paragraph in paragraphs:
         copyrights = _copyrights_from_paragraph(paragraph)
@@ -99,7 +99,7 @@ def toml_from_dep5(dep5: Copyright) -> str:
     """Given a Copyright object, return an equivalent REUSE.toml string."""
     header = _header_from_dep5_header(dep5.header)
     annotations = _annotations_from_paragraphs(dep5.all_files_paragraphs())
-    result: Dict[str, Any] = {"version": REUSE_TOML_VERSION}
+    result: dict[str, Any] = {"version": REUSE_TOML_VERSION}
     result.update(header)
     result["annotations"] = annotations
     return tomlkit.dumps(result)
diff --git a/src/reuse/covered_files.py b/src/reuse/covered_files.py
index 753e643b9..549b331f7 100644
--- a/src/reuse/covered_files.py
+++ b/src/reuse/covered_files.py
@@ -12,14 +12,14 @@
 import logging
 import os
 from pathlib import Path
-from typing import Collection, Generator, Optional, Set, cast
+from typing import Collection, Generator, Optional, cast
 
 from . import (
     _IGNORE_DIR_PATTERNS,
     _IGNORE_FILE_PATTERNS,
     _IGNORE_MESON_PARENT_DIR_PATTERNS,
 )
-from ._util import StrPath, is_relative_to
+from ._util import StrPath
 from .vcs import VCSStrategy
 
 _LOGGER = logging.getLogger(__name__)
@@ -60,8 +60,7 @@ def is_path_ignored(
 
     elif path.is_dir():
         if subset_files is not None and not any(
-            is_relative_to(Path(file_), path.resolve())
-            for file_ in subset_files
+            Path(file_).is_relative_to(path.resolve()) for file_ in subset_files
         ):
             return True
         for pattern in _IGNORE_DIR_PATTERNS:
@@ -102,7 +101,7 @@ def iter_files(
     directory = Path(directory)
     if subset_files is not None:
         subset_files = cast(
-            Set[Path], {Path(file_).resolve() for file_ in subset_files}
+            set[Path], {Path(file_).resolve() for file_ in subset_files}
         )
 
     for root_str, dirs, files in os.walk(directory):
diff --git a/src/reuse/global_licensing.py b/src/reuse/global_licensing.py
index 18fef001f..f0b1b9b77 100644
--- a/src/reuse/global_licensing.py
+++ b/src/reuse/global_licensing.py
@@ -17,12 +17,8 @@
     Any,
     Callable,
     Collection,
-    Dict,
     Generator,
-    List,
     Optional,
-    Set,
-    Tuple,
     Type,
     TypeVar,
     Union,
@@ -39,7 +35,7 @@
 from license_expression import ExpressionError
 
 from . import ReuseException, ReuseInfo, SourceType
-from ._util import _LICENSING, StrPath, is_relative_to
+from ._util import _LICENSING, StrPath
 from .covered_files import iter_files
 from .vcs import VCSStrategy
 
@@ -198,18 +194,18 @@ def _str_to_global_precedence(value: Any) -> PrecedenceType:
 
 
 @overload
-def _str_to_set(value: str) -> Set[str]: ...
+def _str_to_set(value: str) -> set[str]: ...
 
 
 @overload
-def _str_to_set(value: Union[None, _T, Collection[_T]]) -> Set[_T]: ...
+def _str_to_set(value: Union[None, _T, Collection[_T]]) -> set[_T]: ...
 
 
 def _str_to_set(
     value: Union[str, None, _T, Collection[_T]]
-) -> Union[Set[str], Set[_T]]:
+) -> Union[set[str], set[_T]]:
     if value is None:
-        return cast(Set[str], set())
+        return cast(set[str], set())
     if isinstance(value, str):
         return {value}
     if hasattr(value, "__iter__"):
@@ -217,7 +213,7 @@ def _str_to_set(
     return {value}
 
 
-def _str_to_set_of_expr(value: Any) -> Set[Expression]:
+def _str_to_set_of_expr(value: Any) -> set[Expression]:
     value = _str_to_set(value)
     result = set()
     for expression in value:
@@ -255,7 +251,7 @@ def from_file(cls, path: StrPath, **kwargs: Any) -> "GlobalLicensing":
     @abstractmethod
     def reuse_info_of(
         self, path: StrPath
-    ) -> Dict[PrecedenceType, List[ReuseInfo]]:
+    ) -> dict[PrecedenceType, list[ReuseInfo]]:
         """Find the REUSE information of *path* defined in the configuration.
         The path must be relative to the root of a
         :class:`reuse.project.Project`.
@@ -290,7 +286,7 @@ def from_file(cls, path: StrPath, **kwargs: Any) -> "ReuseDep5":
 
     def reuse_info_of(
         self, path: StrPath
-    ) -> Dict[PrecedenceType, List[ReuseInfo]]:
+    ) -> dict[PrecedenceType, list[ReuseInfo]]:
         path = PurePath(path).as_posix()
         result = self.dep5_copyright.find_files_paragraph(path)
 
@@ -330,19 +326,19 @@ class AnnotationsItem:
         "spdx_expressions": "SPDX-License-Identifier",
     }
 
-    paths: Set[str] = attrs.field(
+    paths: set[str] = attrs.field(
         converter=_str_to_set,
         validator=_validate_collection_of(set, str, optional=False),
     )
     precedence: PrecedenceType = attrs.field(
         converter=_str_to_global_precedence, default=PrecedenceType.CLOSEST
     )
-    copyright_lines: Set[str] = attrs.field(
+    copyright_lines: set[str] = attrs.field(
         converter=_str_to_set,
         validator=_validate_collection_of(set, str, optional=True),
         default=None,
     )
-    spdx_expressions: Set[Expression] = attrs.field(
+    spdx_expressions: set[Expression] = attrs.field(
         converter=_str_to_set_of_expr,
         validator=_validate_collection_of(set, Expression, optional=True),
         default=None,
@@ -394,7 +390,7 @@ def translate(path: str) -> str:
         )
 
     @classmethod
-    def from_dict(cls, values: Dict[str, Any]) -> "AnnotationsItem":
+    def from_dict(cls, values: dict[str, Any]) -> "AnnotationsItem":
         """Create an :class:`AnnotationsItem` from a dictionary that uses the
         key-value pairs for an [[annotations]] table in REUSE.toml.
         """
@@ -423,12 +419,12 @@ class ReuseTOML(GlobalLicensing):
     """A class that contains the data parsed from a REUSE.toml file."""
 
     version: int = attrs.field(validator=_instance_of(int))
-    annotations: List[AnnotationsItem] = attrs.field(
+    annotations: list[AnnotationsItem] = attrs.field(
         validator=_validate_collection_of(list, AnnotationsItem, optional=True)
     )
 
     @classmethod
-    def from_dict(cls, values: Dict[str, Any], source: str) -> "ReuseTOML":
+    def from_dict(cls, values: dict[str, Any], source: str) -> "ReuseTOML":
         """Create a :class:`ReuseTOML` from the dict version of REUSE.toml."""
         new_dict = {}
         new_dict["version"] = values.get("version")
@@ -481,7 +477,7 @@ def find_annotations_item(self, path: StrPath) -> Optional[AnnotationsItem]:
 
     def reuse_info_of(
         self, path: StrPath
-    ) -> Dict[PrecedenceType, List[ReuseInfo]]:
+    ) -> dict[PrecedenceType, list[ReuseInfo]]:
         path = PurePath(path).as_posix()
         item = self.find_annotations_item(path)
         if item:
@@ -508,7 +504,7 @@ def directory(self) -> PurePath:
 class NestedReuseTOML(GlobalLicensing):
     """A class that represents a hierarchy of :class:`ReuseTOML` objects."""
 
-    reuse_tomls: List[ReuseTOML] = attrs.field()
+    reuse_tomls: list[ReuseTOML] = attrs.field()
 
     @classmethod
     def from_file(cls, path: StrPath, **kwargs: Any) -> "GlobalLicensing":
@@ -531,10 +527,10 @@ def from_file(cls, path: StrPath, **kwargs: Any) -> "GlobalLicensing":
 
     def reuse_info_of(
         self, path: StrPath
-    ) -> Dict[PrecedenceType, List[ReuseInfo]]:
+    ) -> dict[PrecedenceType, list[ReuseInfo]]:
         path = PurePath(path)
 
-        toml_items: List[Tuple[ReuseTOML, AnnotationsItem]] = (
+        toml_items: list[tuple[ReuseTOML, AnnotationsItem]] = (
             self._find_relevant_tomls_and_items(path)
         )
 
@@ -564,7 +560,7 @@ def reuse_info_of(
         # Consider copyright and licensing separately.
         copyright_found = False
         licence_found = False
-        to_keep: List[ReuseInfo] = []
+        to_keep: list[ReuseInfo] = []
         for info in reversed(result[PrecedenceType.CLOSEST]):
             new_info = info.copy(copyright_lines=set(), spdx_expressions=set())
             if not copyright_found and info.copyright_lines:
@@ -604,11 +600,10 @@ def find_reuse_tomls(
             if item.name == "REUSE.toml"
         )
 
-    def _find_relevant_tomls(self, path: StrPath) -> List[ReuseTOML]:
+    def _find_relevant_tomls(self, path: StrPath) -> list[ReuseTOML]:
         found = []
         for toml in self.reuse_tomls:
-            # TODO: When Python 3.8 is dropped, use is_relative_to instead.
-            if is_relative_to(PurePath(path), toml.directory):
+            if PurePath(path).is_relative_to(toml.directory):
                 found.append(toml)
         # Sort from topmost to deepest directory.
         found.sort(key=lambda toml: toml.directory.parts)
@@ -616,7 +611,7 @@ def _find_relevant_tomls(self, path: StrPath) -> List[ReuseTOML]:
 
     def _find_relevant_tomls_and_items(
         self, path: StrPath
-    ) -> List[Tuple[ReuseTOML, AnnotationsItem]]:
+    ) -> list[tuple[ReuseTOML, AnnotationsItem]]:
         # *path* is relative to the Project root, which is the *source* of
         # NestedReuseTOML, which itself is a relative (to CWD) or absolute
         # path.
@@ -624,7 +619,7 @@ def _find_relevant_tomls_and_items(
         adjusted_path = PurePath(self.source) / path
 
         tomls = self._find_relevant_tomls(adjusted_path)
-        toml_items: List[Tuple[ReuseTOML, AnnotationsItem]] = []
+        toml_items: list[tuple[ReuseTOML, AnnotationsItem]] = []
         for toml in tomls:
             relpath = adjusted_path.relative_to(toml.directory)
             item = toml.find_annotations_item(relpath)
diff --git a/src/reuse/header.py b/src/reuse/header.py
index b125e9464..bf7b9abb7 100644
--- a/src/reuse/header.py
+++ b/src/reuse/header.py
@@ -17,7 +17,7 @@
 import logging
 import re
 from gettext import gettext as _
-from typing import NamedTuple, Optional, Sequence, Tuple, Type, cast
+from typing import NamedTuple, Optional, Sequence, Type, cast
 
 from boolean.boolean import ParseError
 from jinja2 import Environment, PackageLoader, Template
@@ -206,7 +206,7 @@ def _find_first_spdx_comment(
     raise MissingReuseInfo()
 
 
-def _extract_shebang(prefix: str, text: str) -> Tuple[str, str]:
+def _extract_shebang(prefix: str, text: str) -> tuple[str, str]:
     """Remove all lines that start with the shebang prefix from *text*. Return a
     tuple of (shebang, reduced_text).
     """
diff --git a/src/reuse/project.py b/src/reuse/project.py
index 3f6148931..c4f12038c 100644
--- a/src/reuse/project.py
+++ b/src/reuse/project.py
@@ -17,16 +17,7 @@
 from collections import defaultdict
 from gettext import gettext as _
 from pathlib import Path
-from typing import (
-    Collection,
-    DefaultDict,
-    Dict,
-    Iterator,
-    List,
-    NamedTuple,
-    Optional,
-    Type,
-)
+from typing import Collection, Iterator, NamedTuple, Optional, Type
 
 import attrs
 from binaryornot.check import is_binary
@@ -81,10 +72,10 @@ class Project:
     global_licensing: Optional[GlobalLicensing] = None
 
     # TODO: I want to get rid of these, or somehow refactor this mess.
-    license_map: Dict[str, Dict] = attrs.field()
-    licenses: Dict[str, Path] = attrs.field(factory=dict)
+    license_map: dict[str, dict] = attrs.field()
+    licenses: dict[str, Path] = attrs.field(factory=dict)
 
-    licenses_without_extension: Dict[str, Path] = attrs.field(
+    licenses_without_extension: dict[str, Path] = attrs.field(
         init=False, factory=dict
     )
 
@@ -93,7 +84,7 @@ def _default_vcs_strategy(self) -> VCSStrategy:
         return VCSStrategyNone(self.root)
 
     @license_map.default
-    def _default_license_map(self) -> Dict[str, Dict]:
+    def _default_license_map(self) -> dict[str, dict]:
         license_map = LICENSE_MAP.copy()
         license_map.update(EXCEPTION_MAP)
         return license_map
@@ -218,7 +209,7 @@ def subset_files(
             vcs_strategy=self.vcs_strategy,
         )
 
-    def reuse_info_of(self, path: StrPath) -> List[ReuseInfo]:
+    def reuse_info_of(self, path: StrPath) -> list[ReuseInfo]:
         """Return REUSE info of *path*.
 
         This function will return any REUSE information that it can find: from
@@ -250,11 +241,11 @@ def reuse_info_of(self, path: StrPath) -> List[ReuseInfo]:
 
         # This means that only one 'source' of licensing/copyright information
         # is captured in ReuseInfo
-        global_results: "DefaultDict[PrecedenceType, List[ReuseInfo]]" = (
+        global_results: defaultdict[PrecedenceType, list[ReuseInfo]] = (
             defaultdict(list)
         )
         file_result = ReuseInfo()
-        result: List[ReuseInfo] = []
+        result: list[ReuseInfo] = []
 
         # Search the global licensing file for REUSE information.
         if self.global_licensing:
@@ -327,7 +318,7 @@ def find_global_licensing(
         include_submodules: bool = False,
         include_meson_subprojects: bool = False,
         vcs_strategy: Optional[VCSStrategy] = None,
-    ) -> List[GlobalLicensingFound]:
+    ) -> list[GlobalLicensingFound]:
         """Find the path and corresponding class of a project directory's
         :class:`GlobalLicensing`.
 
@@ -335,7 +326,7 @@ def find_global_licensing(
             GlobalLicensingConflict: if more than one global licensing config
                 file is present.
         """
-        candidates: List[GlobalLicensingFound] = []
+        candidates: list[GlobalLicensingFound] = []
         dep5_path = root / ".reuse/dep5"
         if (dep5_path).exists():
             # Sneaky workaround to not print this warning.
@@ -377,7 +368,7 @@ def find_global_licensing(
 
     @classmethod
     def _global_licensing_from_found(
-        cls, found: List[GlobalLicensingFound], root: StrPath
+        cls, found: list[GlobalLicensingFound], root: StrPath
     ) -> GlobalLicensing:
         if len(found) == 1 and found[0].cls == ReuseDep5:
             return ReuseDep5.from_file(found[0].path)
@@ -403,12 +394,12 @@ def _identifier_of_license(self, path: Path) -> str:
             f"Could not find SPDX License Identifier for {path}"
         )
 
-    def _find_licenses(self) -> Dict[str, Path]:
+    def _find_licenses(self) -> dict[str, Path]:
         """Return a dictionary of all licenses in the project, with their SPDX
         identifiers as names and paths as values.
         """
         # TODO: This method does more than one thing. We ought to simplify it.
-        license_files: Dict[str, Path] = {}
+        license_files: dict[str, Path] = {}
 
         directory = str(self.root / "LICENSES/**")
         for path_str in glob.iglob(directory, recursive=True):
diff --git a/src/reuse/report.py b/src/reuse/report.py
index 70032d0b3..fff28242b 100644
--- a/src/reuse/report.py
+++ b/src/reuse/report.py
@@ -24,13 +24,10 @@
 from typing import (
     Any,
     Collection,
-    Dict,
     Iterable,
-    List,
     NamedTuple,
     Optional,
     Protocol,
-    Set,
     cast,
 )
 from uuid import uuid4
@@ -167,16 +164,16 @@ class ProjectReportSubsetProtocol(Protocol):
     """
 
     path: StrPath
-    missing_licenses: Dict[str, Set[Path]]
-    read_errors: Set[Path]
-    file_reports: Set["FileReport"]
+    missing_licenses: dict[str, set[Path]]
+    read_errors: set[Path]
+    file_reports: set["FileReport"]
 
     @property
-    def files_without_licenses(self) -> Set[Path]:
+    def files_without_licenses(self) -> set[Path]:
         """Set of paths that have no licensing information."""
 
     @property
-    def files_without_copyright(self) -> Set[Path]:
+    def files_without_copyright(self) -> set[Path]:
         """Set of paths that have no copyright information."""
 
     @property
@@ -189,23 +186,23 @@ class ProjectReport:  # pylint: disable=too-many-instance-attributes
 
     def __init__(self, do_checksum: bool = True):
         self.path: StrPath = ""
-        self.licenses: Dict[str, Path] = {}
-        self.missing_licenses: Dict[str, Set[Path]] = {}
-        self.bad_licenses: Dict[str, Set[Path]] = {}
-        self.deprecated_licenses: Set[str] = set()
-        self.read_errors: Set[Path] = set()
-        self.file_reports: Set[FileReport] = set()
-        self.licenses_without_extension: Dict[str, Path] = {}
+        self.licenses: dict[str, Path] = {}
+        self.missing_licenses: dict[str, set[Path]] = {}
+        self.bad_licenses: dict[str, set[Path]] = {}
+        self.deprecated_licenses: set[str] = set()
+        self.read_errors: set[Path] = set()
+        self.file_reports: set[FileReport] = set()
+        self.licenses_without_extension: dict[str, Path] = {}
 
         self.do_checksum = do_checksum
 
-        self._unused_licenses: Optional[Set[str]] = None
-        self._used_licenses: Optional[Set[str]] = None
-        self._files_without_licenses: Optional[Set[Path]] = None
-        self._files_without_copyright: Optional[Set[Path]] = None
+        self._unused_licenses: Optional[set[str]] = None
+        self._used_licenses: Optional[set[str]] = None
+        self._files_without_licenses: Optional[set[Path]] = None
+        self._files_without_copyright: Optional[set[Path]] = None
         self._is_compliant: Optional[bool] = None
 
-    def to_dict_lint(self) -> Dict[str, Any]:
+    def to_dict_lint(self) -> dict[str, Any]:
         """Collects and formats data relevant to linting from report and returns
         it as a dictionary.
 
@@ -213,7 +210,7 @@ def to_dict_lint(self) -> Dict[str, Any]:
             Dictionary containing data from the ProjectReport object.
         """
         # Setup report data container
-        data: Dict[str, Any] = {
+        data: dict[str, Any] = {
             "non_compliant": {
                 "missing_licenses": self.missing_licenses,
                 "unused_licenses": [str(file) for file in self.unused_licenses],
@@ -419,7 +416,7 @@ def generate(
         return project_report
 
     @property
-    def used_licenses(self) -> Set[str]:
+    def used_licenses(self) -> set[str]:
         """Set of license identifiers that are found in file reports."""
         if self._used_licenses is not None:
             return self._used_licenses
@@ -432,7 +429,7 @@ def used_licenses(self) -> Set[str]:
         return self._used_licenses
 
     @property
-    def unused_licenses(self) -> Set[str]:
+    def unused_licenses(self) -> set[str]:
         """Set of license identifiers that are not found in any file report."""
         if self._unused_licenses is not None:
             return self._unused_licenses
@@ -450,7 +447,7 @@ def unused_licenses(self) -> Set[str]:
         return self._unused_licenses
 
     @property
-    def files_without_licenses(self) -> Set[Path]:
+    def files_without_licenses(self) -> set[Path]:
         """Set of paths that have no licensing information."""
         if self._files_without_licenses is not None:
             return self._files_without_licenses
@@ -464,7 +461,7 @@ def files_without_licenses(self) -> Set[Path]:
         return self._files_without_licenses
 
     @property
-    def files_without_copyright(self) -> Set[Path]:
+    def files_without_copyright(self) -> set[Path]:
         """Set of paths that have no copyright information."""
         if self._files_without_copyright is not None:
             return self._files_without_copyright
@@ -499,7 +496,7 @@ def is_compliant(self) -> bool:
         return self._is_compliant
 
     @property
-    def recommendations(self) -> List[str]:
+    def recommendations(self) -> list[str]:
         """Generate help for next steps based on found REUSE issues"""
         recommendations = []
 
@@ -589,9 +586,9 @@ class ProjectSubsetReport:
 
     def __init__(self) -> None:
         self.path: StrPath = ""
-        self.missing_licenses: Dict[str, Set[Path]] = {}
-        self.read_errors: Set[Path] = set()
-        self.file_reports: Set[FileReport] = set()
+        self.missing_licenses: dict[str, set[Path]] = {}
+        self.read_errors: set[Path] = set()
+        self.file_reports: set[FileReport] = set()
 
     @classmethod
     def generate(
@@ -632,7 +629,7 @@ def generate(
         return subset_report
 
     @property
-    def files_without_licenses(self) -> Set[Path]:
+    def files_without_licenses(self) -> set[Path]:
         """Set of paths that have no licensing information."""
         return {
             file_report.path
@@ -641,7 +638,7 @@ def files_without_licenses(self) -> Set[Path]:
         }
 
     @property
-    def files_without_copyright(self) -> Set[Path]:
+    def files_without_copyright(self) -> set[Path]:
         """Set of paths that have no copyright information."""
         return {
             file_report.path
@@ -670,24 +667,22 @@ def __init__(self, name: str, path: StrPath, do_checksum: bool = True):
         self.path = Path(path)
         self.do_checksum = do_checksum
 
-        self.reuse_infos: List[ReuseInfo] = []
+        self.reuse_infos: list[ReuseInfo] = []
 
         self.spdx_id: Optional[str] = None
         self.chk_sum: Optional[str] = None
-        self.licenses_in_file: List[str] = []
+        self.licenses_in_file: list[str] = []
         self.license_concluded: str = ""
         self.copyright: str = ""
 
-        self.bad_licenses: Set[str] = set()
-        self.missing_licenses: Set[str] = set()
+        self.bad_licenses: set[str] = set()
+        self.missing_licenses: set[str] = set()
 
-    def to_dict_lint(self) -> Dict[str, Any]:
+    def to_dict_lint(self) -> dict[str, Any]:
         """Turn the report into a json-like dictionary with exclusively
         information relevant for linting.
         """
         return {
-            # This gets rid of the './' prefix. In Python 3.9, use
-            # str.removeprefix.
             "path": PurePath(self.name).as_posix(),
             "copyrights": [
                 {
diff --git a/src/reuse/vcs.py b/src/reuse/vcs.py
index daca12da8..eaec9f7ac 100644
--- a/src/reuse/vcs.py
+++ b/src/reuse/vcs.py
@@ -15,7 +15,7 @@
 from abc import ABC, abstractmethod
 from inspect import isclass
 from pathlib import Path
-from typing import TYPE_CHECKING, Generator, Optional, Set, Type
+from typing import TYPE_CHECKING, Generator, Optional, Type
 
 from ._util import (
     GIT_EXE,
@@ -99,7 +99,7 @@ def __init__(self, root: StrPath):
         self._all_ignored_files = self._find_all_ignored_files()
         self._submodules = self._find_submodules()
 
-    def _find_all_ignored_files(self) -> Set[Path]:
+    def _find_all_ignored_files(self) -> set[Path]:
         """Return a set of all files ignored by git. If a whole directory is
         ignored, don't return all files inside of it.
         """
@@ -121,7 +121,7 @@ def _find_all_ignored_files(self) -> Set[Path]:
         all_files = result.stdout.decode("utf-8").split("\0")
         return {Path(file_) for file_ in all_files}
 
-    def _find_submodules(self) -> Set[Path]:
+    def _find_submodules(self) -> set[Path]:
         command = [
             str(self.EXE),
             "config",
@@ -191,7 +191,7 @@ def __init__(self, root: StrPath):
             raise FileNotFoundError("Could not find binary for Mercurial")
         self._all_ignored_files = self._find_all_ignored_files()
 
-    def _find_all_ignored_files(self) -> Set[Path]:
+    def _find_all_ignored_files(self) -> set[Path]:
         """Return a set of all files ignored by mercurial. If a whole directory
         is ignored, don't return all files inside of it.
         """
@@ -258,7 +258,7 @@ def __init__(self, root: StrPath):
             raise FileNotFoundError("Could not find binary for Jujutsu")
         self._all_tracked_files = self._find_all_tracked_files()
 
-    def _find_all_tracked_files(self) -> Set[Path]:
+    def _find_all_tracked_files(self) -> set[Path]:
         """
         Return a set of all files tracked in the current jj revision
         """
@@ -323,7 +323,7 @@ def __init__(self, root: StrPath):
             raise FileNotFoundError("Could not find binary for Pijul")
         self._all_tracked_files = self._find_all_tracked_files()
 
-    def _find_all_tracked_files(self) -> Set[Path]:
+    def _find_all_tracked_files(self) -> set[Path]:
         """Return a set of all files tracked by pijul."""
         command = [str(self.EXE), "list"]
         result = execute_command(command, _LOGGER, cwd=self.root)