diff --git a/pyproject.toml b/pyproject.toml
index 3e18ffe99e2..3e409a54153 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -31,7 +31,6 @@ ignore = [
 
 [tool.ruff.lint.per-file-ignores]
 "!python/**/**.py" = ["ANN"]
-"python/servo/**.py" = ["ANN"]
 "**/test.py" = ["ANN"]
 "**/*_tests.py" = ["ANN"]
 "**/tests/**/*.py" = ["ANN"]
diff --git a/python/servo/bootstrap_commands.py b/python/servo/bootstrap_commands.py
index 41b72f13fb3..da3d215e74d 100644
--- a/python/servo/bootstrap_commands.py
+++ b/python/servo/bootstrap_commands.py
@@ -40,7 +40,7 @@ class MachCommands(CommandBase):
     @CommandArgument("--force", "-f", action="store_true", help="Boostrap without confirmation")
     @CommandArgument("--skip-platform", action="store_true", help="Skip platform bootstrapping.")
     @CommandArgument("--skip-lints", action="store_true", help="Skip tool necessary for linting.")
-    def bootstrap(self, force=False, skip_platform=False, skip_lints=False) -> int:
+    def bootstrap(self, force: bool = False, skip_platform: bool = False, skip_lints: bool = False) -> int:
         # Note: This entry point isn't actually invoked by ./mach bootstrap.
         # ./mach bootstrap calls mach_bootstrap.bootstrap_command_only so that
         # it can install dependencies without needing mach's dependencies
@@ -57,7 +57,7 @@ class MachCommands(CommandBase):
         category="bootstrap",
     )
     @CommandArgument("--force", "-f", action="store_true", help="Boostrap without confirmation")
-    def bootstrap_gstreamer(self, force=False) -> int:
+    def bootstrap_gstreamer(self, force: bool = False) -> int:
         try:
             servo.platform.get().bootstrap_gstreamer(force)
         except NotImplementedError as exception:
@@ -66,7 +66,7 @@ class MachCommands(CommandBase):
         return 0
 
     @Command("update-hsts-preload", description="Download the HSTS preload list", category="bootstrap")
-    def bootstrap_hsts_preload(self, force=False) -> None:
+    def bootstrap_hsts_preload(self, force: bool = False) -> None:
         preload_filename = "hsts_preload.fstmap"
         preload_path = path.join(self.context.topdir, "resources")
 
@@ -104,7 +104,7 @@ class MachCommands(CommandBase):
         description="Download the public domains list and update resources/public_domains.txt",
         category="bootstrap",
     )
-    def bootstrap_pub_suffix(self, force=False) -> None:
+    def bootstrap_pub_suffix(self, force: bool = False) -> None:
         list_url = "https://publicsuffix.org/list/public_suffix_list.dat"
         dst_filename = path.join(self.context.topdir, "resources", "public_domains.txt")
         not_implemented_case = re.compile(r"^[^*]+\*")
diff --git a/python/servo/build_commands.py b/python/servo/build_commands.py
index cf90776c4e9..f70d00af536 100644
--- a/python/servo/build_commands.py
+++ b/python/servo/build_commands.py
@@ -18,7 +18,7 @@ import subprocess
 import sys
 
 from time import time
-from typing import Optional, List, Dict, Union
+from typing import Optional, Union, Any
 
 from mach.decorators import (
     CommandArgument,
@@ -54,7 +54,7 @@ SUPPORTED_TSAN_TARGETS = [
 ]
 
 
-def get_rustc_llvm_version() -> Optional[List[int]]:
+def get_rustc_llvm_version() -> Optional[list[int]]:
     """Determine the LLVM version of `rustc` and return it as a List[major, minor, patch, ...]
 
     In some cases we want to ensure that the LLVM version of rustc and clang match, e.g.
@@ -94,14 +94,14 @@ class MachCommands(CommandBase):
     def build(
         self,
         build_type: BuildType,
-        jobs=None,
-        params=None,
-        no_package=False,
-        verbose=False,
-        very_verbose=False,
+        jobs: str | None = None,
+        params: list[str] | None = None,
+        no_package: bool = False,
+        verbose: bool = False,
+        very_verbose: bool = False,
         sanitizer: SanitizerKind = SanitizerKind.NONE,
-        flavor=None,
-        **kwargs,
+        flavor: str | None = None,
+        **kwargs: Any,
     ) -> int:
         opts = params or []
 
@@ -200,7 +200,7 @@ class MachCommands(CommandBase):
     @CommandArgument("--manifest-path", default=None, help="Path to the manifest to the package to clean")
     @CommandArgument("--verbose", "-v", action="store_true", help="Print verbose output")
     @CommandArgument("params", nargs="...", help="Command-line arguments to be passed through to Cargo")
-    def clean(self, manifest_path=None, params=[], verbose=False) -> None:
+    def clean(self, manifest_path: str | None = None, params: list[str] = [], verbose: bool = False) -> None:
         self.ensure_bootstrapped()
 
         virtualenv_path = path.join(self.get_top_dir(), ".venv")
@@ -215,7 +215,7 @@ class MachCommands(CommandBase):
         return check_call(["cargo", "clean"] + opts, env=self.build_env(), verbose=verbose)
 
     def build_sanitizer_env(
-        self, env: Dict, opts: List[str], kwargs, target_triple: str, sanitizer: SanitizerKind = SanitizerKind.NONE
+        self, env: dict, opts: list[str], kwargs: Any, target_triple: str, sanitizer: SanitizerKind = SanitizerKind.NONE
     ) -> None:
         if sanitizer.is_none():
             return
diff --git a/python/servo/command_base.py b/python/servo/command_base.py
index 522917abd84..74a14d018e3 100644
--- a/python/servo/command_base.py
+++ b/python/servo/command_base.py
@@ -19,6 +19,7 @@ import shutil
 import subprocess
 import sys
 import tarfile
+from tarfile import TarInfo
 import urllib
 import zipfile
 import urllib.error
@@ -28,7 +29,8 @@ from enum import Enum
 from glob import glob
 from os import path
 from subprocess import PIPE, CompletedProcess
-from typing import Any, Dict, List, Optional, Union, LiteralString, cast
+from typing import Any, Optional, Union, LiteralString, cast
+from collections.abc import Generator, Callable
 from xml.etree.ElementTree import XML
 
 import toml
@@ -93,7 +95,7 @@ class BuildType:
 
 
 @contextlib.contextmanager
-def cd(new_path: str):
+def cd(new_path: str) -> Generator:
     """Context manager for changing the current working directory"""
     previous_path = os.getcwd()
     try:
@@ -104,7 +106,7 @@ def cd(new_path: str):
 
 
 @contextlib.contextmanager
-def setlocale(name: str):
+def setlocale(name: str) -> Generator:
     """Context manager for changing the current locale"""
     saved_locale = locale.setlocale(locale.LC_ALL)
     try:
@@ -113,7 +115,7 @@ def setlocale(name: str):
         locale.setlocale(locale.LC_ALL, saved_locale)
 
 
-def find_dep_path_newest(package, bin_path):
+def find_dep_path_newest(package: str, bin_path: str) -> str | None:
     deps_path = path.join(path.split(bin_path)[0], "build")
     candidates = []
     with cd(deps_path):
@@ -126,12 +128,12 @@ def find_dep_path_newest(package, bin_path):
     return None
 
 
-def archive_deterministically(dir_to_archive, dest_archive, prepend_path=None) -> None:
+def archive_deterministically(dir_to_archive: str, dest_archive: str, prepend_path: str | None = None) -> None:
     """Create a .tar.gz archive in a deterministic (reproducible) manner.
 
     See https://reproducible-builds.org/docs/archives/ for more details."""
 
-    def reset(tarinfo):
+    def reset(tarinfo: TarInfo) -> TarInfo:
         """Helper to reset owner/group and modification time for tar entries"""
         tarinfo.uid = tarinfo.gid = 0
         tarinfo.uname = tarinfo.gname = "root"
@@ -177,7 +179,7 @@ def archive_deterministically(dir_to_archive, dest_archive, prepend_path=None) -
         os.rename(temp_file, dest_archive)
 
 
-def call(*args, **kwargs) -> int:
+def call(*args: Any, **kwargs: Any) -> int:
     """Wrap `subprocess.call`, printing the command if verbose=True."""
     verbose = kwargs.pop("verbose", False)
     if verbose:
@@ -188,7 +190,7 @@ def call(*args, **kwargs) -> int:
     return subprocess.call(*args, **kwargs)
 
 
-def check_output(*args, **kwargs) -> Union[str, bytes]:
+def check_output(*args: Any, **kwargs: Any) -> Union[str, bytes]:
     """Wrap `subprocess.call`, printing the command if verbose=True."""
     verbose = kwargs.pop("verbose", False)
     if verbose:
@@ -199,7 +201,7 @@ def check_output(*args, **kwargs) -> Union[str, bytes]:
     return subprocess.check_output(*args, **kwargs)
 
 
-def check_call(*args, **kwargs) -> None:
+def check_call(*args: Any, **kwargs: Any) -> None:
     """Wrap `subprocess.check_call`, printing the command if verbose=True.
 
     Also fix any unicode-containing `env`, for subprocess"""
@@ -239,10 +241,10 @@ def is_linux() -> bool:
 
 
 class BuildNotFound(Exception):
-    def __init__(self, message) -> None:
+    def __init__(self, message: str) -> None:
         self.message = message
 
-    def __str__(self):
+    def __str__(self) -> str:
         return self.message
 
 
@@ -253,7 +255,7 @@ class CommandBase(object):
 
     target: BuildTarget
 
-    def __init__(self, context) -> None:
+    def __init__(self, context: Any) -> None:
         self.context = context
         self.enable_media = False
         self.features = []
@@ -321,7 +323,7 @@ class CommandBase(object):
 
     _rust_toolchain = None
 
-    def rust_toolchain(self):
+    def rust_toolchain(self) -> str:
         if self._rust_toolchain:
             return self._rust_toolchain
 
@@ -329,7 +331,7 @@ class CommandBase(object):
         self._rust_toolchain = toml.load(toolchain_file)["toolchain"]["channel"]
         return self._rust_toolchain
 
-    def get_top_dir(self):
+    def get_top_dir(self) -> str:
         return self.context.topdir
 
     def get_binary_path(self, build_type: BuildType, sanitizer: SanitizerKind = SanitizerKind.NONE) -> str:
@@ -356,7 +358,7 @@ class CommandBase(object):
         if os.path.exists(mounted_volume):
             self.detach_volume(mounted_volume)
 
-    def mount_dmg(self, dmg_path) -> None:
+    def mount_dmg(self, dmg_path: str) -> None:
         print("Mounting dmg {}".format(dmg_path))
         try:
             subprocess.check_call(["hdiutil", "attach", dmg_path])
@@ -394,7 +396,7 @@ class CommandBase(object):
             return path.join(destination_folder, "servo", "servo")
         return path.join(destination_folder, "servo")
 
-    def get_nightly_binary_path(self, nightly_date) -> str | None:
+    def get_nightly_binary_path(self, nightly_date: str | None) -> str | None:
         if nightly_date is None:
             return
         if not nightly_date:
@@ -462,7 +464,7 @@ class CommandBase(object):
 
         return self.get_executable(destination_folder)
 
-    def msvc_package_dir(self, package) -> str:
+    def msvc_package_dir(self, package: str) -> str:
         return servo.platform.windows.get_dependency_dir(package)
 
     def build_env(self) -> dict[str, str]:
@@ -531,8 +533,11 @@ class CommandBase(object):
 
     @staticmethod
     def common_command_arguments(
-        build_configuration=False, build_type=False, binary_selection=False, package_configuration=False
-    ):
+        build_configuration: bool = False,
+        build_type: bool = False,
+        binary_selection: bool = False,
+        package_configuration: bool = False,
+    ) -> Callable:
         decorators = []
         if build_type or binary_selection:
             decorators += [
@@ -654,8 +659,8 @@ class CommandBase(object):
                 CommandArgument("--nightly", "-n", default=None, help="Specify a YYYY-MM-DD nightly build to run"),
             ]
 
-        def decorator_function(original_function):
-            def configuration_decorator(self, *args, **kwargs):
+        def decorator_function(original_function: Callable) -> Callable:
+            def configuration_decorator(self: CommandBase, *args: Any, **kwargs: Any) -> Callable:
                 if build_type or binary_selection:
                     # If `build_type` already exists in kwargs we are doing a recursive dispatch.
                     if "build_type" not in kwargs:
@@ -680,7 +685,10 @@ class CommandBase(object):
                         kwargs["servo_binary"] = (
                             kwargs.get("bin")
                             or self.get_nightly_binary_path(kwargs.get("nightly"))
-                            or self.get_binary_path(kwargs.get("build_type"), sanitizer=kwargs.get("sanitizer"))
+                            or self.get_binary_path(
+                                cast(BuildType, kwargs.get("build_type")),
+                                sanitizer=cast(SanitizerKind, kwargs.get("sanitizer")),
+                            )
                         )
                     kwargs.pop("bin")
                     kwargs.pop("nightly")
@@ -699,8 +707,8 @@ class CommandBase(object):
         return decorator_function
 
     @staticmethod
-    def allow_target_configuration(original_function):
-        def target_configuration_decorator(self, *args, **kwargs):
+    def allow_target_configuration(original_function: Callable) -> Callable:
+        def target_configuration_decorator(self: CommandBase, *args: Any, **kwargs: Any) -> Callable:
             self.configure_build_target(kwargs, suppress_log=True)
             kwargs.pop("target", False)
             kwargs.pop("android", False)
@@ -741,7 +749,7 @@ class CommandBase(object):
         else:
             return BuildType.custom(profile)
 
-    def configure_build_target(self, kwargs: Dict[str, Any], suppress_log: bool = False) -> None:
+    def configure_build_target(self, kwargs: dict[str, Any], suppress_log: bool = False) -> None:
         if hasattr(self.context, "target"):
             # This call is for a dispatched command and we've already configured
             # the target, so just use it.
@@ -778,7 +786,7 @@ class CommandBase(object):
         if self.target.is_cross_build() and not suppress_log:
             print(f"Targeting '{self.target.triple()}' for cross-compilation")
 
-    def is_media_enabled(self, media_stack: Optional[str]):
+    def is_media_enabled(self, media_stack: Optional[str]) -> bool:
         """Determine whether media is enabled based on the value of the build target
         platform and the value of the '--media-stack' command-line argument.
         Returns true if media is enabled."""
@@ -803,16 +811,16 @@ class CommandBase(object):
     def run_cargo_build_like_command(
         self,
         command: str,
-        cargo_args: List[str],
-        env=None,
-        verbose=False,
-        debug_mozjs=False,
-        with_debug_assertions=False,
-        with_frame_pointer=False,
-        use_crown=False,
-        capture_output=False,
+        cargo_args: list[str],
+        env: dict[str, Any] | None = None,
+        verbose: bool = False,
+        debug_mozjs: bool = False,
+        with_debug_assertions: bool = False,
+        with_frame_pointer: bool = False,
+        use_crown: bool = False,
+        capture_output: bool = False,
         target_override: Optional[str] = None,
-        **_kwargs,
+        **_kwargs: Any,
     ) -> CompletedProcess[bytes] | int:
         env = cast(dict[str, str], env or self.build_env())
 
@@ -888,14 +896,14 @@ class CommandBase(object):
 
         return call(["cargo", command] + args + cargo_args, env=env, verbose=verbose)
 
-    def android_adb_path(self, env) -> LiteralString:
+    def android_adb_path(self, env: dict[str, Any]) -> LiteralString:
         if "ANDROID_SDK_ROOT" in env:
             sdk_adb = path.join(env["ANDROID_SDK_ROOT"], "platform-tools", "adb")
             if path.exists(sdk_adb):
                 return sdk_adb
         return "adb"
 
-    def android_emulator_path(self, env) -> LiteralString:
+    def android_emulator_path(self, env: dict[str, Any]) -> LiteralString:
         if "ANDROID_SDK_ROOT" in env:
             sdk_adb = path.join(env["ANDROID_SDK_ROOT"], "emulator", "emulator")
             if path.exists(sdk_adb):
@@ -919,7 +927,7 @@ class CommandBase(object):
         if self.target.triple() not in installed_targets:
             check_call(["rustup", "target", "add", self.target.triple()], cwd=self.context.topdir)
 
-    def ensure_clobbered(self, target_dir=None) -> None:
+    def ensure_clobbered(self, target_dir: str | None = None) -> None:
         if target_dir is None:
             target_dir = util.get_target_dir()
         auto = True if os.environ.get("AUTOCLOBBER", False) else False
diff --git a/python/servo/devenv_commands.py b/python/servo/devenv_commands.py
index 87ad307ccff..9739272905d 100644
--- a/python/servo/devenv_commands.py
+++ b/python/servo/devenv_commands.py
@@ -9,6 +9,7 @@
 
 from subprocess import CompletedProcess
 import json
+from typing import Any
 
 from mach.decorators import (
     Command,
@@ -27,7 +28,7 @@ class MachCommands(CommandBase):
         "params", default=None, nargs="...", help="Command-line arguments to be passed through to cargo check"
     )
     @CommandBase.common_command_arguments(build_configuration=True, build_type=False)
-    def check(self, params, **kwargs) -> int:
+    def check(self, params: list[str], **kwargs: Any) -> int:
         if not params:
             params = []
 
@@ -42,7 +43,7 @@ class MachCommands(CommandBase):
 
     @Command("rustc", description="Run the Rust compiler", category="devenv")
     @CommandArgument("params", default=None, nargs="...", help="Command-line arguments to be passed through to rustc")
-    def rustc(self, params) -> int:
+    def rustc(self, params: list[str]) -> int:
         if params is None:
             params = []
 
@@ -54,7 +55,7 @@ class MachCommands(CommandBase):
         "params", default=None, nargs="...", help="Command-line arguments to be passed through to cargo-fix"
     )
     @CommandBase.common_command_arguments(build_configuration=True, build_type=False)
-    def cargo_fix(self, params, **kwargs) -> int:
+    def cargo_fix(self, params: list[str], **kwargs: Any) -> int:
         if not params:
             params = []
 
@@ -73,7 +74,7 @@ class MachCommands(CommandBase):
         help="Emit the clippy warnings in the Github Actions annotations format",
     )
     @CommandBase.common_command_arguments(build_configuration=True, build_type=False)
-    def cargo_clippy(self, params, github_annotations=False, **kwargs) -> int:
+    def cargo_clippy(self, params: list[str], github_annotations: bool = False, **kwargs: Any) -> int:
         if not params:
             params = []
 
diff --git a/python/servo/gstreamer.py b/python/servo/gstreamer.py
index 763f294298d..593443a1732 100644
--- a/python/servo/gstreamer.py
+++ b/python/servo/gstreamer.py
@@ -11,7 +11,7 @@ import os.path
 import shutil
 import subprocess
 import sys
-from typing import Set
+from collections.abc import Set
 
 # This file is called as a script from components/servo/build.rs, so
 # we need to explicitly modify the search path here.
diff --git a/python/servo/mutation/init.py b/python/servo/mutation/init.py
index f1a2c5ee077..f58449a3530 100644
--- a/python/servo/mutation/init.py
+++ b/python/servo/mutation/init.py
@@ -18,7 +18,7 @@ import random
 test_summary = {test.Status.KILLED: 0, test.Status.SURVIVED: 0, test.Status.SKIPPED: 0, test.Status.UNEXPECTED: 0}
 
 
-def get_folders_list(path):
+def get_folders_list(path: str) -> list[str]:
     folder_list = []
     for filename in listdir(path):
         if isdir(join(path, filename)):
diff --git a/python/servo/mutation/mutator.py b/python/servo/mutation/mutator.py
index aa61ef677ea..72ed9c7796b 100644
--- a/python/servo/mutation/mutator.py
+++ b/python/servo/mutation/mutator.py
@@ -11,14 +11,14 @@ import fileinput
 import re
 from re import Match
 import random
-from typing import Iterator
+from collections.abc import Iterator
 
 
 def is_comment(line: str) -> Match[str] | None:
     return re.search(r"\/\/.*", line)
 
 
-def init_variables(if_blocks):
+def init_variables(if_blocks: list[int]) -> tuple[int, int, int, int, int]:
     random_index = random.randint(0, len(if_blocks) - 1)
     start_counter = 0
     end_counter = 0
@@ -27,7 +27,7 @@ def init_variables(if_blocks):
     return random_index, start_counter, end_counter, lines_to_delete, line_to_mutate
 
 
-def deleteStatements(file_name, line_numbers) -> None:
+def deleteStatements(file_name: str, line_numbers: list[int]) -> None:
     for line in fileinput.input(file_name, inplace=True):
         if fileinput.lineno() not in line_numbers:
             print(line.rstrip())
@@ -38,7 +38,7 @@ class Strategy:
         self._strategy_name = ""
         self._replace_strategy = {}
 
-    def mutate(self, file_name):
+    def mutate(self, file_name: str) -> int:
         line_numbers = []
         for line in fileinput.input(file_name):
             if not is_comment(line) and re.search(self._replace_strategy["regex"], line):
@@ -140,7 +140,7 @@ class DeleteIfBlock(Strategy):
         self.if_block = r"^\s+if\s(.+)\s\{"
         self.else_block = r"\selse(.+)\{"
 
-    def mutate(self, file_name):
+    def mutate(self, file_name: str) -> int:
         code_lines = []
         if_blocks = []
         for line in fileinput.input(file_name):
@@ -192,8 +192,8 @@ def get_strategies() -> Iterator[Strategy]:
 
 
 class Mutator:
-    def __init__(self, strategy) -> None:
+    def __init__(self, strategy: Strategy) -> None:
         self._strategy = strategy
 
-    def mutate(self, file_name):
+    def mutate(self, file_name: str) -> int:
         return self._strategy.mutate(file_name)
diff --git a/python/servo/package_commands.py b/python/servo/package_commands.py
index 9921877c6eb..eda2676eab9 100644
--- a/python/servo/package_commands.py
+++ b/python/servo/package_commands.py
@@ -10,7 +10,7 @@
 from datetime import datetime
 import random
 import time
-from typing import List
+from collections.abc import Generator
 from github import Github
 
 import hashlib
@@ -68,14 +68,14 @@ PACKAGES = {
 }
 
 
-def packages_for_platform(platform):
+def packages_for_platform(platform: str) -> Generator[str]:
     target_dir = get_target_dir()
 
     for package in PACKAGES[platform]:
         yield path.join(target_dir, package)
 
 
-def listfiles(directory) -> list[str]:
+def listfiles(directory: str) -> list[str]:
     return [f for f in os.listdir(directory) if path.isfile(path.join(directory, f))]
 
 
@@ -85,7 +85,7 @@ def copy_windows_dependencies(binary_path: str, destination: str) -> None:
             shutil.copy(path.join(binary_path, f), destination)
 
 
-def check_call_with_randomized_backoff(args: List[str], retries: int) -> int:
+def check_call_with_randomized_backoff(args: list[str], retries: int) -> int:
     """
     Run the given command-line arguments via `subprocess.check_call()`. If the command
     fails sleep for a random number of seconds between 2 and 5 and then try to the command
@@ -111,7 +111,9 @@ class PackageCommands(CommandBase):
     @CommandArgument("--target", "-t", default=None, help="Package for given target platform")
     @CommandBase.common_command_arguments(build_configuration=False, build_type=True, package_configuration=True)
     @CommandBase.allow_target_configuration
-    def package(self, build_type: BuildType, flavor=None, sanitizer: SanitizerKind = SanitizerKind.NONE) -> int | None:
+    def package(
+        self, build_type: BuildType, flavor: str | None = None, sanitizer: SanitizerKind = SanitizerKind.NONE
+    ) -> int | None:
         env = self.build_env()
         binary_path = self.get_binary_path(build_type, sanitizer=sanitizer)
         dir_to_root = self.get_top_dir()
@@ -398,10 +400,10 @@ class PackageCommands(CommandBase):
     def install(
         self,
         build_type: BuildType,
-        emulator=False,
-        usb=False,
+        emulator: bool = False,
+        usb: bool = False,
         sanitizer: SanitizerKind = SanitizerKind.NONE,
-        flavor=None,
+        flavor: str | None = None,
     ) -> int:
         env = self.build_env()
         try:
@@ -453,10 +455,10 @@ class PackageCommands(CommandBase):
     @CommandArgument(
         "--github-release-id", default=None, type=int, help="The github release to upload the nightly builds."
     )
-    def upload_nightly(self, platform, secret_from_environment, github_release_id) -> int:
+    def upload_nightly(self, platform: str, secret_from_environment: bool, github_release_id: int | None) -> int:
         import boto3
 
-        def get_s3_secret():
+        def get_s3_secret() -> tuple:
             aws_access_key = None
             aws_secret_access_key = None
             if secret_from_environment:
@@ -465,13 +467,13 @@ class PackageCommands(CommandBase):
                 aws_secret_access_key = secret["aws_secret_access_key"]
             return (aws_access_key, aws_secret_access_key)
 
-        def nightly_filename(package, timestamp) -> str:
+        def nightly_filename(package: str, timestamp: datetime) -> str:
             return "{}-{}".format(
                 timestamp.isoformat() + "Z",  # The `Z` denotes UTC
                 path.basename(package),
             )
 
-        def upload_to_github_release(platform, package: str, package_hash: str) -> None:
+        def upload_to_github_release(platform: str, package: str, package_hash: str) -> None:
             if not github_release_id:
                 return
 
@@ -488,7 +490,7 @@ class PackageCommands(CommandBase):
                 package_hash_fileobj, package_hash_fileobj.getbuffer().nbytes, name=f"{asset_name}.sha256"
             )
 
-        def upload_to_s3(platform, package: str, package_hash: str, timestamp: datetime) -> None:
+        def upload_to_s3(platform: str, package: str, package_hash: str, timestamp: datetime) -> None:
             (aws_access_key, aws_secret_access_key) = get_s3_secret()
             s3 = boto3.client("s3", aws_access_key_id=aws_access_key, aws_secret_access_key=aws_secret_access_key)
 
diff --git a/python/servo/platform/__init__.py b/python/servo/platform/__init__.py
index e996ac2ccdd..077b668a529 100644
--- a/python/servo/platform/__init__.py
+++ b/python/servo/platform/__init__.py
@@ -47,7 +47,7 @@ def host_triple() -> str:
     return f"{cpu_type}-{os_type}"
 
 
-def get():
+def get():  # noqa
     # pylint: disable=global-statement
     global __platform__
     if __platform__:
diff --git a/python/servo/platform/build_target.py b/python/servo/platform/build_target.py
index c0341816634..8bdd0d9fb4b 100644
--- a/python/servo/platform/build_target.py
+++ b/python/servo/platform/build_target.py
@@ -20,7 +20,7 @@ from enum import Enum
 
 from os import path
 from packaging.version import parse as parse_version
-from typing import Any, Dict, Optional
+from typing import Any, Optional
 
 import servo.platform
 import servo.util as util
@@ -70,7 +70,7 @@ class BuildTarget(object):
     def binary_name(self) -> str:
         return f"servo{servo.platform.get().executable_suffix()}"
 
-    def configure_build_environment(self, env: Dict[str, str], config: Dict[str, Any], topdir: pathlib.Path) -> None:
+    def configure_build_environment(self, env: dict[str, str], config: dict[str, Any], topdir: pathlib.Path) -> None:
         pass
 
     def is_cross_build(self) -> bool:
@@ -88,7 +88,7 @@ class CrossBuildTarget(BuildTarget):
 class AndroidTarget(CrossBuildTarget):
     DEFAULT_TRIPLE = "aarch64-linux-android"
 
-    def ndk_configuration(self) -> Dict[str, str]:
+    def ndk_configuration(self) -> dict[str, str]:
         target = self.triple()
         config = {}
         if target == "armv7-linux-androideabi":
@@ -125,7 +125,7 @@ class AndroidTarget(CrossBuildTarget):
 
         return config
 
-    def configure_build_environment(self, env: Dict[str, str], config: Dict[str, Any], topdir: pathlib.Path) -> None:
+    def configure_build_environment(self, env: dict[str, str], config: dict[str, Any], topdir: pathlib.Path) -> None:
         # Paths to Android build tools:
         if config["android"]["sdk"]:
             env["ANDROID_SDK_ROOT"] = config["android"]["sdk"]
@@ -296,7 +296,7 @@ class AndroidTarget(CrossBuildTarget):
 class OpenHarmonyTarget(CrossBuildTarget):
     DEFAULT_TRIPLE = "aarch64-unknown-linux-ohos"
 
-    def configure_build_environment(self, env: Dict[str, str], config: Dict[str, Any], topdir: pathlib.Path) -> None:
+    def configure_build_environment(self, env: dict[str, str], config: dict[str, Any], topdir: pathlib.Path) -> None:
         # Paths to OpenHarmony SDK and build tools:
         # Note: `OHOS_SDK_NATIVE` is the CMake variable name the `hvigor` build-system
         # uses for the native directory of the SDK, so we use the same name to be consistent.
diff --git a/python/servo/platform/linux.py b/python/servo/platform/linux.py
index 25a55d7caa1..8464a338e81 100644
--- a/python/servo/platform/linux.py
+++ b/python/servo/platform/linux.py
@@ -11,7 +11,7 @@ import distro
 import os
 import subprocess
 import shutil
-from typing import Optional
+from typing import Optional, Any
 
 from .base import Base
 from .build_target import BuildTarget
@@ -164,7 +164,7 @@ GSTREAMER_URL = (
 
 
 class Linux(Base):
-    def __init__(self, *args, **kwargs) -> None:
+    def __init__(self, *args: str, **kwargs: Any) -> None:
         super().__init__(*args, **kwargs)
         self.is_linux = True
         self.distro = distro.name()
diff --git a/python/servo/platform/macos.py b/python/servo/platform/macos.py
index 89a95b985b5..020efdde47d 100644
--- a/python/servo/platform/macos.py
+++ b/python/servo/platform/macos.py
@@ -10,7 +10,7 @@
 import os
 import subprocess
 import tempfile
-from typing import Optional
+from typing import Optional, Any
 
 from .. import util
 from .base import Base
@@ -24,7 +24,7 @@ GSTREAMER_ROOT = "/Library/Frameworks/GStreamer.framework/Versions/1.0"
 
 
 class MacOS(Base):
-    def __init__(self, *args, **kwargs) -> None:
+    def __init__(self, *args: str, **kwargs: Any) -> None:
         super().__init__(*args, **kwargs)
         self.is_macos = True
 
diff --git a/python/servo/post_build_commands.py b/python/servo/post_build_commands.py
index 40bb09038ab..f0ecb34ab45 100644
--- a/python/servo/post_build_commands.py
+++ b/python/servo/post_build_commands.py
@@ -13,7 +13,7 @@ import os.path as path
 import subprocess
 from subprocess import CompletedProcess
 from shutil import copy2
-from typing import List
+from typing import Any
 
 import mozdebug
 
@@ -36,7 +36,7 @@ from servo.platform.build_target import is_android
 ANDROID_APP_NAME = "org.servo.servoshell"
 
 
-def read_file(filename, if_exists=False) -> str | None:
+def read_file(filename: str, if_exists: bool = False) -> str | None:
     if if_exists and not path.exists(filename):
         return None
     with open(filename) as f:
@@ -44,7 +44,7 @@ def read_file(filename, if_exists=False) -> str | None:
 
 
 # Copied from Python 3.3+'s shlex.quote()
-def shell_quote(arg: str):
+def shell_quote(arg: str) -> str:
     # use single quotes, and put single quotes into double quotes
     # the string $'b is then quoted as '$'"'"'b'
     return "'" + arg.replace("'", "'\"'\"'") + "'"
@@ -75,26 +75,26 @@ class PostBuildCommands(CommandBase):
     def run(
         self,
         servo_binary: str,
-        params,
-        debugger=False,
-        debugger_cmd=None,
-        headless=False,
-        software=False,
-        emulator=False,
-        usb=False,
+        params: list[str],
+        debugger: bool = False,
+        debugger_cmd: str | None = None,
+        headless: bool = False,
+        software: bool = False,
+        emulator: bool = False,
+        usb: bool = False,
     ) -> int | None:
         return self._run(servo_binary, params, debugger, debugger_cmd, headless, software, emulator, usb)
 
     def _run(
         self,
         servo_binary: str,
-        params,
-        debugger=False,
-        debugger_cmd=None,
-        headless=False,
-        software=False,
-        emulator=False,
-        usb=False,
+        params: list[str],
+        debugger: bool = False,
+        debugger_cmd: str | None = None,
+        headless: bool = False,
+        software: bool = False,
+        emulator: bool = False,
+        usb: bool = False,
     ) -> int | None:
         env = self.build_env()
         env["RUST_BACKTRACE"] = "1"
@@ -194,7 +194,7 @@ class PostBuildCommands(CommandBase):
 
     @Command("android-emulator", description="Run the Android emulator", category="post-build")
     @CommandArgument("args", nargs="...", help="Command-line arguments to be passed through to the emulator")
-    def android_emulator(self, args=None) -> int:
+    def android_emulator(self, args: list[str] | None = None) -> int:
         if not args:
             args = []
             print("AVDs created by `./mach bootstrap-android` are servo-arm and servo-x86.")
@@ -204,7 +204,7 @@ class PostBuildCommands(CommandBase):
     @Command("rr-record", description="Run Servo whilst recording execution with rr", category="post-build")
     @CommandArgument("params", nargs="...", help="Command-line arguments to be passed through to Servo")
     @CommandBase.common_command_arguments(binary_selection=True)
-    def rr_record(self, servo_binary: str, params=[]) -> None:
+    def rr_record(self, servo_binary: str, params: list[str] = []) -> None:
         env = self.build_env()
         env["RUST_BACKTRACE"] = "1"
 
@@ -235,7 +235,7 @@ class PostBuildCommands(CommandBase):
     @Command("doc", description="Generate documentation", category="post-build")
     @CommandArgument("params", nargs="...", help="Command-line arguments to be passed through to cargo doc")
     @CommandBase.common_command_arguments(build_configuration=True, build_type=False)
-    def doc(self, params: List[str], **kwargs) -> CompletedProcess[bytes] | int | None:
+    def doc(self, params: list[str], **kwargs: Any) -> CompletedProcess[bytes] | int | None:
         self.ensure_bootstrapped()
 
         docs = path.join(servo.util.get_target_dir(), "doc")
diff --git a/python/servo/testing_commands.py b/python/servo/testing_commands.py
index 4ed241aea49..fff3c9b5526 100644
--- a/python/servo/testing_commands.py
+++ b/python/servo/testing_commands.py
@@ -118,7 +118,7 @@ class MachCommands(CommandBase):
     DEFAULT_RENDER_MODE = "cpu"
     HELP_RENDER_MODE = "Value can be 'cpu', 'gpu' or 'both' (default " + DEFAULT_RENDER_MODE + ")"
 
-    def __init__(self, context) -> None:
+    def __init__(self, context: Any) -> None:
         CommandBase.__init__(self, context)
         if not hasattr(self.context, "built_tests"):
             self.context.built_tests = False
@@ -127,7 +127,7 @@ class MachCommands(CommandBase):
     @CommandArgument("--base", default=None, help="the base URL for testcases")
     @CommandArgument("--date", default=None, help="the datestamp for the data")
     @CommandArgument("--submit", "-a", default=False, action="store_true", help="submit the data to perfherder")
-    def test_perf(self, base=None, date=None, submit=False) -> int:
+    def test_perf(self, base: str | None = None, date: str | None = None, submit: bool = False) -> int:
         env = self.build_env()
         cmd = ["bash", "test_perf.sh"]
         if base:
@@ -147,7 +147,13 @@ class MachCommands(CommandBase):
     )
     @CommandBase.common_command_arguments(build_configuration=True, build_type=True)
     def test_unit(
-        self, build_type: BuildType, test_name=None, package=None, bench=False, nocapture=False, **kwargs
+        self,
+        build_type: BuildType,
+        test_name: list[str] | None = None,
+        package: str | None = None,
+        bench: bool = False,
+        nocapture: bool = False,
+        **kwargs: Any,
     ) -> int:
         if test_name is None:
             test_name = []
@@ -265,7 +271,7 @@ class MachCommands(CommandBase):
         action="store_true",
         help="Emit tidy warnings in the Github Actions annotations format",
     )
-    def test_tidy(self, all_files, no_progress, github_annotations) -> int:
+    def test_tidy(self, all_files: bool, no_progress: bool, github_annotations: bool) -> int:
         tidy_failed = tidy.scan(not all_files, not no_progress, github_annotations)
 
         print("\r ➤  Checking formatting of Rust files...")
@@ -299,7 +305,7 @@ class MachCommands(CommandBase):
     @CommandArgument(
         "tests", default=None, nargs="...", help="Specific WebIDL tests to run, relative to the tests directory"
     )
-    def test_scripts(self, verbose, very_verbose, all, tests) -> int:
+    def test_scripts(self, verbose: bool, very_verbose: bool, all: bool, tests: list[str]) -> int:
         if very_verbose:
             logging.getLogger().level = logging.DEBUG
         elif verbose:
@@ -357,7 +363,7 @@ class MachCommands(CommandBase):
     @Command("test-devtools", description="Run tests for devtools.", category="testing")
     @CommandArgument("test_names", nargs=argparse.REMAINDER, help="Only run tests that match these patterns")
     @CommandBase.common_command_arguments(build_type=True)
-    def test_devtools(self, build_type: BuildType, test_names: list[str], **kwargs) -> int:
+    def test_devtools(self, build_type: BuildType, test_names: list[str], **kwargs: Any) -> int:
         print("Running devtools tests...")
         passed = servo.devtools_tests.run_tests(SCRIPT_PATH, build_type, test_names)
         return 0 if passed else 1
@@ -369,7 +375,7 @@ class MachCommands(CommandBase):
         parser=wpt.create_parser,
     )
     @CommandBase.common_command_arguments(build_configuration=False, build_type=True)
-    def test_wpt_failure(self, build_type: BuildType, **kwargs) -> bool:
+    def test_wpt_failure(self, build_type: BuildType, **kwargs: Any) -> bool:
         kwargs["pause_after_test"] = False
         kwargs["include"] = ["infrastructure/failing-test.html"]
         return not self._test_wpt(build_type=build_type, **kwargs)
@@ -378,11 +384,11 @@ class MachCommands(CommandBase):
         "test-wpt", description="Run the regular web platform test suite", category="testing", parser=wpt.create_parser
     )
     @CommandBase.common_command_arguments(binary_selection=True)
-    def test_wpt(self, servo_binary: str, **kwargs):
+    def test_wpt(self, servo_binary: str, **kwargs: Any) -> int:
         return self._test_wpt(servo_binary, **kwargs)
 
     @CommandBase.allow_target_configuration
-    def _test_wpt(self, servo_binary: str, **kwargs) -> int:
+    def _test_wpt(self, servo_binary: str, **kwargs: Any) -> int:
         # TODO(mrobinson): Why do we pass the wrong binary path in when running WPT on Android?
         return_value = wpt.run.run_tests(servo_binary, **kwargs)
         return return_value if not kwargs["always_succeed"] else 0
@@ -393,7 +399,7 @@ class MachCommands(CommandBase):
         category="testing",
         parser=wpt.manifestupdate.create_parser,
     )
-    def update_manifest(self, **kwargs) -> int:
+    def update_manifest(self, **kwargs: Any) -> int:
         return wpt.manifestupdate.update(check_clean=False)
 
     @Command("fmt", description="Format Rust, Python, and TOML files", category="testing")
@@ -411,7 +417,7 @@ class MachCommands(CommandBase):
     @Command(
         "update-wpt", description="Update the web platform tests", category="testing", parser=wpt.update.create_parser
     )
-    def update_wpt(self, **kwargs) -> int:
+    def update_wpt(self, **kwargs: Any) -> int:
         patch = kwargs.get("patch", False)
         if not patch and kwargs["sync"]:
             print("Are you sure you don't want a patch?")
@@ -427,7 +433,7 @@ class MachCommands(CommandBase):
     @CommandArgument("tests", default=["recommended"], nargs="...", help="Specific tests to run")
     @CommandArgument("--bmf-output", default=None, help="Specify BMF JSON output file")
     @CommandBase.common_command_arguments(binary_selection=True)
-    def test_dromaeo(self, tests, servo_binary: str, bmf_output: str | None = None) -> None:
+    def test_dromaeo(self, tests: list[str], servo_binary: str, bmf_output: str | None = None) -> None:
         return self.dromaeo_test_runner(tests, servo_binary, bmf_output)
 
     @Command("test-speedometer", description="Run servo's speedometer", category="testing")
@@ -455,7 +461,7 @@ class MachCommands(CommandBase):
     @CommandArgument(
         "params", default=None, nargs="...", help=" filepaths of output files of two runs of dromaeo test "
     )
-    def compare_dromaeo(self, params) -> None:
+    def compare_dromaeo(self, params: list[str]) -> None:
         prev_op_filename = params[0]
         cur_op_filename = params[1]
         result = {"Test": [], "Prev_Time": [], "Cur_Time": [], "Difference(%)": []}
@@ -552,7 +558,7 @@ class MachCommands(CommandBase):
 
         return call([run_file, cmd, bin_path, base_dir])
 
-    def dromaeo_test_runner(self, tests, binary: str, bmf_output: str | None) -> None:
+    def dromaeo_test_runner(self, tests: list[str], binary: str, bmf_output: str | None) -> None:
         base_dir = path.abspath(path.join("tests", "dromaeo"))
         dromaeo_dir = path.join(base_dir, "dromaeo")
         run_file = path.join(base_dir, "run_dromaeo.py")
@@ -582,7 +588,7 @@ class MachCommands(CommandBase):
         output = dict()
         profile = "" if profile is None else profile + "/"
 
-        def parse_speedometer_result(result) -> None:
+        def parse_speedometer_result(result: dict[str, Any]) -> None:
             if result["unit"] == "ms":
                 output[profile + f"Speedometer/{result['name']}"] = {
                     "latency": {  # speedometer has ms we need to convert to ns
@@ -700,7 +706,7 @@ class MachCommands(CommandBase):
         description="Update the net unit tests with cookie tests from http-state",
         category="testing",
     )
-    def update_net_cookies(self):
+    def update_net_cookies(self) -> int:
         cache_dir = path.join(self.config["tools"]["cache-dir"], "tests")
         run_file = path.abspath(
             path.join(PROJECT_TOPLEVEL_PATH, "components", "net", "tests", "cookie_http_state_utils.py")
@@ -713,7 +719,7 @@ class MachCommands(CommandBase):
         "update-webgl", description="Update the WebGL conformance suite tests from Khronos repo", category="testing"
     )
     @CommandArgument("--version", default="2.0.0", help="WebGL conformance suite version")
-    def update_webgl(self, version=None):
+    def update_webgl(self, version: str | None = None) -> None:
         base_dir = path.abspath(path.join(PROJECT_TOPLEVEL_PATH, "tests", "wpt", "mozilla", "tests", "webgl"))
         run_file = path.join(base_dir, "tools", "import-conformance-tests.py")
         dest_folder = path.join(base_dir, "conformance-%s" % version)
@@ -729,7 +735,7 @@ class MachCommands(CommandBase):
     @Command("update-webgpu", description="Update the WebGPU conformance test suite", category="testing")
     @CommandArgument("--repo", "-r", default="https://github.com/gpuweb/cts", help="Repo to vendor cts from")
     @CommandArgument("--checkout", "-c", default="main", help="Branch or commit of repo")
-    def cts(self, repo="https://github.com/gpuweb/cts", checkout="main"):
+    def cts(self, repo: str = "https://github.com/gpuweb/cts", checkout: str = "main") -> int:
         tdir = path.join(self.context.topdir, "tests/wpt/webgpu/tests")
         clone_dir = path.join(tdir, "cts_clone")
         # clone
@@ -786,7 +792,7 @@ class MachCommands(CommandBase):
     )
     @CommandArgument("params", nargs="...", help="Command-line arguments to be passed through to Servo")
     @CommandBase.common_command_arguments(binary_selection=True)
-    def smoketest(self, servo_binary: str, params, **kwargs) -> int | None:
+    def smoketest(self, servo_binary: str, params: list[str], **kwargs: Any) -> int | None:
         # We pass `-f` here so that any thread panic will cause Servo to exit,
         # preventing a panic from hanging execution. This means that these kind
         # of panics won't cause timeouts on CI.
diff --git a/python/servo/try_parser.py b/python/servo/try_parser.py
index bd3f42cd1fe..8e240139f11 100644
--- a/python/servo/try_parser.py
+++ b/python/servo/try_parser.py
@@ -13,7 +13,7 @@ from __future__ import annotations
 
 import json
 import sys
-from typing import ClassVar, List, Optional
+from typing import ClassVar, Optional, Any
 import unittest
 import logging
 
@@ -44,7 +44,7 @@ class JobConfig(object):
     number_of_wpt_chunks: int = 20
     # These are the fields that must match in between two JobConfigs for them to be able to be
     # merged. If you modify any of the fields above, make sure to update this line as well.
-    merge_compatibility_fields: ClassVar[List[str]] = ["workflow", "profile", "wpt_args", "build_args"]
+    merge_compatibility_fields: ClassVar[list[str]] = ["workflow", "profile", "wpt_args", "build_args"]
 
     def merge(self, other: JobConfig) -> bool:
         """Try to merge another job with this job. Returns True if merging is successful
@@ -177,7 +177,7 @@ def handle_modifier(config: Optional[JobConfig], s: str) -> Optional[JobConfig]:
 
 
 class Encoder(json.JSONEncoder):
-    def default(self, o):
+    def default(self, o: Any) -> Any:
         if isinstance(o, (Config, JobConfig)):
             return o.__dict__
         return json.JSONEncoder.default(self, o)
@@ -236,7 +236,7 @@ class Config(object):
                 return
         self.matrix.append(job)
 
-    def to_json(self, **kwargs) -> str:
+    def to_json(self, **kwargs: Any) -> str:
         return json.dumps(self, cls=Encoder, **kwargs)
 
 
diff --git a/python/servo/util.py b/python/servo/util.py
index 03be77e005e..65b701f25e7 100644
--- a/python/servo/util.py
+++ b/python/servo/util.py
@@ -7,6 +7,7 @@
 # option. This file may not be copied, modified, or distributed
 # except according to those terms.
 
+from os import PathLike
 import hashlib
 import os
 import os.path
@@ -18,7 +19,8 @@ import urllib.error
 import urllib.request
 import zipfile
 from zipfile import ZipInfo
-from typing import Dict, List, Union
+from typing import Union, Any
+from collections.abc import Callable
 
 from io import BufferedIOBase, BytesIO
 from socket import error as socket_error
@@ -27,13 +29,13 @@ SCRIPT_PATH = os.path.abspath(os.path.dirname(__file__))
 SERVO_ROOT = os.path.abspath(os.path.join(SCRIPT_PATH, "..", ".."))
 
 
-def remove_readonly(func, path, _) -> None:
+def remove_readonly(func: Callable[[str], None], path: str, _: Any) -> None:
     "Clear the readonly bit and reattempt the removal"
     os.chmod(path, stat.S_IWRITE)
     func(path)
 
 
-def delete(path) -> None:
+def delete(path: str) -> None:
     if os.path.isdir(path) and not os.path.islink(path):
         shutil.rmtree(path, onerror=remove_readonly)
     else:
@@ -123,7 +125,7 @@ def download_file(description: str, url: str, destination_path: str) -> None:
 # https://stackoverflow.com/questions/39296101/python-zipfile-removes-execute-permissions-from-binaries
 # In particular, we want the executable bit for executable files.
 class ZipFileWithUnixPermissions(zipfile.ZipFile):
-    def extract(self, member, path=None, pwd=None) -> str:
+    def extract(self, member: ZipInfo | str, path: PathLike[str] | str | None = None, pwd: bytes | None = None) -> str:
         if not isinstance(member, zipfile.ZipInfo):
             member = self.getinfo(member)
 
@@ -137,7 +139,7 @@ class ZipFileWithUnixPermissions(zipfile.ZipFile):
         return extracted
 
     # For Python 3.x
-    def _extract_member(self, member: ZipInfo, targetpath, pwd) -> str:
+    def _extract_member(self, member: ZipInfo, targetpath: PathLike[str] | str, pwd: bytes | None) -> str:
         if int(sys.version_info[0]) >= 3:
             if not isinstance(member, zipfile.ZipInfo):
                 member = self.getinfo(member)
@@ -154,7 +156,7 @@ class ZipFileWithUnixPermissions(zipfile.ZipFile):
             return super(ZipFileWithUnixPermissions, self)._extract_member(member, targetpath, pwd)
 
 
-def extract(src, dst, movedir=None, remove=True) -> None:
+def extract(src: str, dst: str, movedir: PathLike[str] | str | None = None, remove: bool = True) -> None:
     assert src.endswith(".zip")
     ZipFileWithUnixPermissions(src).extractall(dst)
 
@@ -169,7 +171,7 @@ def extract(src, dst, movedir=None, remove=True) -> None:
         os.remove(src)
 
 
-def check_hash(filename, expected, algorithm) -> None:
+def check_hash(filename: str, expected: str, algorithm: str) -> None:
     hasher = hashlib.new(algorithm)
     with open(filename, "rb") as f:
         while True:
@@ -182,11 +184,11 @@ def check_hash(filename, expected, algorithm) -> None:
         sys.exit(1)
 
 
-def get_default_cache_dir(topdir) -> str:
+def get_default_cache_dir(topdir: str) -> str:
     return os.environ.get("SERVO_CACHE_DIR", os.path.join(topdir, ".servo"))
 
 
-def append_paths_to_env(env: Dict[str, str], key: str, paths: Union[str, List[str]]) -> None:
+def append_paths_to_env(env: dict[str, str], key: str, paths: Union[str, list[str]]) -> None:
     if isinstance(paths, list):
         paths = os.pathsep.join(paths)
 
@@ -198,7 +200,7 @@ def append_paths_to_env(env: Dict[str, str], key: str, paths: Union[str, List[st
     env[key] = new_value
 
 
-def prepend_paths_to_env(env: Dict[str, str], key: str, paths: Union[str, List[str]]) -> None:
+def prepend_paths_to_env(env: dict[str, str], key: str, paths: Union[str, list[str]]) -> None:
     if isinstance(paths, list):
         paths = os.pathsep.join(paths)
 
diff --git a/python/servo/visual_studio.py b/python/servo/visual_studio.py
index 6a615b531c6..f6e1ad3d8a8 100644
--- a/python/servo/visual_studio.py
+++ b/python/servo/visual_studio.py
@@ -7,12 +7,15 @@
 # option. This file may not be copied, modified, or distributed
 # except according to those terms.
 
+from __future__ import annotations
+
 import dataclasses
 import json
 import os
 import subprocess
 import sys
-from typing import Generator, List, Optional
+from typing import Optional
+from collections.abc import Generator
 
 COMPATIBLE_MSVC_VERSIONS = {
     "2019": "16.0",
@@ -30,7 +33,7 @@ class VisualStudioInstallation:
     installation_path: str
     vc_install_path: str
 
-    def __lt__(self, other) -> bool:
+    def __lt__(self, other: VisualStudioInstallation) -> bool:
         return self.version_number < other.version_number
 
 
@@ -108,7 +111,7 @@ def find_compatible_msvc_with_environment_variables() -> Optional[VisualStudioIn
     )
 
 
-def find_msvc_installations() -> List[VisualStudioInstallation]:
+def find_msvc_installations() -> list[VisualStudioInstallation]:
     # First try to find Visual Studio via `vswhere.exe` and in well-known paths.
     installations = list(find_compatible_msvc_with_vswhere())
     installations.extend(find_compatible_msvc_with_path())