diff --git a/src/mobu/business/base.py b/src/mobu/business/base.py
index 5f31c3d8..ec350344 100644
--- a/src/mobu/business/base.py
+++ b/src/mobu/business/base.py
@@ -3,10 +3,11 @@
 from __future__ import annotations
 
 import asyncio
-from asyncio import Queue, QueueEmpty, TimeoutError
+from asyncio import Queue, QueueEmpty
+from collections.abc import AsyncIterable, AsyncIterator
 from datetime import datetime, timezone
 from enum import Enum
-from typing import AsyncIterable, AsyncIterator, TypeVar
+from typing import TypeVar
 
 from structlog import BoundLogger
 
diff --git a/src/mobu/business/jupyterloginloop.py b/src/mobu/business/jupyterloginloop.py
index eba5580f..21e6a66f 100644
--- a/src/mobu/business/jupyterloginloop.py
+++ b/src/mobu/business/jupyterloginloop.py
@@ -9,7 +9,7 @@
 import asyncio
 from dataclasses import dataclass, field
 from datetime import datetime, timezone
-from typing import Dict, Optional
+from typing import Optional
 
 from aiohttp import ClientError, ClientResponseError
 from structlog import BoundLogger
@@ -75,7 +75,7 @@ def __init__(
     async def close(self) -> None:
         await self._client.close()
 
-    def annotations(self) -> Dict[str, str]:
+    def annotations(self) -> dict[str, str]:
         """Timer annotations to use.
 
         Subclasses should override this to add more annotations based on
diff --git a/src/mobu/business/jupyterpythonloop.py b/src/mobu/business/jupyterpythonloop.py
index 8f10c626..3dec84b9 100644
--- a/src/mobu/business/jupyterpythonloop.py
+++ b/src/mobu/business/jupyterpythonloop.py
@@ -6,7 +6,7 @@
 
 from __future__ import annotations
 
-from typing import Dict, Optional
+from typing import Optional
 
 from structlog import BoundLogger
 
@@ -46,7 +46,7 @@ def __init__(
         super().__init__(logger, business_config, user)
         self.node: Optional[str] = None
 
-    def annotations(self) -> Dict[str, str]:
+    def annotations(self) -> dict[str, str]:
         result = super().annotations()
         if self.node:
             result["node"] = self.node
diff --git a/src/mobu/business/notebookrunner.py b/src/mobu/business/notebookrunner.py
index 8461a52c..b294d2fc 100644
--- a/src/mobu/business/notebookrunner.py
+++ b/src/mobu/business/notebookrunner.py
@@ -10,7 +10,7 @@
 import random
 from pathlib import Path
 from tempfile import TemporaryDirectory
-from typing import Any, Dict, List, Optional
+from typing import Any, Optional
 
 from git.repo import Repo
 from structlog import BoundLogger
@@ -38,9 +38,9 @@ def __init__(
         self.running_code: Optional[str] = None
         self._repo_dir = TemporaryDirectory()
         self._repo: Optional[Repo] = None
-        self._notebook_paths: Optional[List[Path]] = None
+        self._notebook_paths: Optional[list[Path]] = None
 
-    def annotations(self) -> Dict[str, str]:
+    def annotations(self) -> dict[str, str]:
         result = super().annotations()
         if self.notebook:
             result["notebook"] = self.notebook.name
@@ -60,7 +60,7 @@ def clone_repo(self) -> None:
         with self.timings.start("clone_repo"):
             self._repo = Repo.clone_from(url, path, branch=branch)
 
-    def find_notebooks(self) -> List[Path]:
+    def find_notebooks(self) -> list[Path]:
         with self.timings.start("find_notebooks"):
             notebooks = [
                 p
@@ -79,7 +79,7 @@ def next_notebook(self) -> None:
             self._notebook_paths = self.find_notebooks()
         self.notebook = self._notebook_paths.pop()
 
-    def read_notebook(self, notebook: Path) -> List[Dict[str, Any]]:
+    def read_notebook(self, notebook: Path) -> list[dict[str, Any]]:
         with self.timings.start("read_notebook", {"notebook": notebook.name}):
             try:
                 notebook_text = notebook.read_text()
diff --git a/src/mobu/business/tapqueryrunner.py b/src/mobu/business/tapqueryrunner.py
index 20e974f2..a3de6a27 100644
--- a/src/mobu/business/tapqueryrunner.py
+++ b/src/mobu/business/tapqueryrunner.py
@@ -7,7 +7,7 @@
 import random
 from concurrent.futures import ThreadPoolExecutor
 from pathlib import Path
-from typing import Dict, Optional, Union
+from typing import Optional
 
 import jinja2
 import pyvo
@@ -87,7 +87,7 @@ def _generate_random_polygon(
             poly.append(dec + r * math.cos(theta))
         return ", ".join([str(x) for x in poly])
 
-    def _generate_parameters(self) -> Dict[str, Union[int, float, str]]:
+    def _generate_parameters(self) -> dict[str, int | float | str]:
         """Generate some random parameters for the query."""
         min_ra = self._params.get("min_ra", 55.0)
         max_ra = self._params.get("max_ra", 70.0)
diff --git a/src/mobu/cachemachine.py b/src/mobu/cachemachine.py
index b43cdfe9..80332fff 100644
--- a/src/mobu/cachemachine.py
+++ b/src/mobu/cachemachine.py
@@ -2,8 +2,6 @@
 
 from __future__ import annotations
 
-from typing import List
-
 from aiohttp import ClientSession
 
 from .config import config
@@ -69,7 +67,7 @@ async def get_recommended(self) -> JupyterImage:
             raise CachemachineError(self._username, "No images found")
         return images[0]
 
-    async def _get_images(self) -> List[JupyterImage]:
+    async def _get_images(self) -> list[JupyterImage]:
         headers = {"Authorization": f"bearer {self._token}"}
         async with self._session.get(self._url, headers=headers) as r:
             if r.status != 200:
diff --git a/src/mobu/config.py b/src/mobu/config.py
index 7b22b590..9235b71f 100644
--- a/src/mobu/config.py
+++ b/src/mobu/config.py
@@ -4,7 +4,6 @@
 
 import os
 from dataclasses import dataclass
-from typing import Optional
 
 __all__ = ["Configuration", "config"]
 
@@ -13,7 +12,7 @@
 class Configuration:
     """Configuration for mobu."""
 
-    alert_hook: Optional[str] = os.getenv("ALERT_HOOK")
+    alert_hook: str | None = os.getenv("ALERT_HOOK")
     """The slack webhook used for alerting exceptions to slack.
 
     Set with the ``ALERT_HOOK`` environment variable.
@@ -21,7 +20,7 @@ class Configuration:
     If not set or set to "None", this feature will be disabled.
     """
 
-    autostart: Optional[str] = os.getenv("AUTOSTART")
+    autostart: str | None = os.getenv("AUTOSTART")
     """The path to a YAML file defining what flocks to automatically start.
 
     The YAML file should, if given, be a list of flock specifications. All
@@ -48,7 +47,7 @@ class Configuration:
     Set with the ``CACHEMACHINE_IMAGE_POLICY`` environment variable.
     """
 
-    gafaelfawr_token: Optional[str] = os.getenv("GAFAELFAWR_TOKEN")
+    gafaelfawr_token: str | None = os.getenv("GAFAELFAWR_TOKEN")
     """The Gafaelfawr admin token to use to create user tokens.
 
     This token is used to make an admin API call to Gafaelfawr to get a token
diff --git a/src/mobu/dependencies/manager.py b/src/mobu/dependencies/manager.py
index 41e84776..9023b22b 100644
--- a/src/mobu/dependencies/manager.py
+++ b/src/mobu/dependencies/manager.py
@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 import asyncio
-from typing import Dict, List, Optional
+from typing import Optional
 
 from aiohttp import ClientSession
 from aiojobs import Scheduler
@@ -19,7 +19,7 @@ class MonkeyBusinessManager:
     """Manages all of the running monkeys."""
 
     def __init__(self) -> None:
-        self._flocks: Dict[str, Flock] = {}
+        self._flocks: dict[str, Flock] = {}
         self._scheduler: Optional[Scheduler] = None
         self._session: Optional[ClientSession] = None
 
@@ -56,10 +56,10 @@ def get_flock(self, name: str) -> Flock:
             raise FlockNotFoundException(name)
         return flock
 
-    def list_flocks(self) -> List[str]:
+    def list_flocks(self) -> list[str]:
         return sorted(self._flocks.keys())
 
-    def summarize_flocks(self) -> List[FlockSummary]:
+    def summarize_flocks(self) -> list[FlockSummary]:
         return [f.summary() for _, f in sorted(self._flocks.items())]
 
     async def stop_flock(self, name: str) -> None:
diff --git a/src/mobu/exceptions.py b/src/mobu/exceptions.py
index c18d8a87..0d76ebf4 100644
--- a/src/mobu/exceptions.py
+++ b/src/mobu/exceptions.py
@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 from datetime import datetime
-from typing import Dict, Optional
+from typing import Optional, Self
 
 from aiohttp import ClientResponse, ClientResponseError
 from safir.datetime import format_datetime_for_logging
@@ -61,7 +61,7 @@ def __init__(self, user: str, msg: str) -> None:
         super().__init__(msg, user)
         self.started_at: Optional[datetime] = None
         self.event: Optional[str] = None
-        self.annotations: Dict[str, str] = {}
+        self.annotations: dict[str, str] = {}
 
     def to_slack(self) -> SlackMessage:
         """Format the error as a Slack Block Kit message.
@@ -174,26 +174,22 @@ class JupyterResponseError(MobuSlackException):
     """Web response error from JupyterHub or JupyterLab."""
 
     @classmethod
-    def from_exception(
-        cls, user: str, exc: ClientResponseError
-    ) -> JupyterResponseError:
+    def from_exception(cls, user: str, exc: ClientResponseError) -> Self:
         return cls(
             url=str(exc.request_info.url),
             user=user,
             status=exc.status,
-            reason=exc.message if exc.message else type(exc).__name__,
+            reason=exc.message or type(exc).__name__,
             method=exc.request_info.method,
         )
 
     @classmethod
-    async def from_response(
-        cls, user: str, response: ClientResponse
-    ) -> JupyterResponseError:
+    async def from_response(cls, user: str, response: ClientResponse) -> Self:
         return cls(
             url=str(response.url),
             user=user,
             status=response.status,
-            reason=response.reason,
+            reason=response.reason or "",
             method=response.method,
             body=await response.text(),
         )
@@ -204,7 +200,7 @@ def __init__(
         url: str,
         user: str,
         status: int,
-        reason: Optional[str],
+        reason: str,
         method: str,
         body: Optional[str] = None,
     ) -> None:
@@ -237,9 +233,7 @@ class JupyterSpawnError(MobuSlackException):
     """The Jupyter Lab pod failed to spawn."""
 
     @classmethod
-    def from_exception(
-        cls, user: str, log: str, exc: Exception
-    ) -> JupyterSpawnError:
+    def from_exception(cls, user: str, log: str, exc: Exception) -> Self:
         return cls(user, log, f"{type(exc).__name__}: {str(exc)}")
 
     def __init__(
diff --git a/src/mobu/jupyterclient.py b/src/mobu/jupyterclient.py
index 73ef130b..dd368027 100644
--- a/src/mobu/jupyterclient.py
+++ b/src/mobu/jupyterclient.py
@@ -11,20 +11,12 @@
 import random
 import re
 import string
+from collections.abc import AsyncIterator, Awaitable, Callable
 from dataclasses import dataclass
 from datetime import datetime, timezone
 from functools import wraps
 from http.cookies import BaseCookie
-from typing import (
-    Any,
-    AsyncIterator,
-    Awaitable,
-    Callable,
-    Dict,
-    Optional,
-    TypeVar,
-    cast,
-)
+from typing import Any, Optional, TypeVar, cast
 from uuid import uuid4
 
 from aiohttp import (
@@ -501,7 +493,7 @@ def _remove_ansi_escapes(string: str) -> str:
         """
         return _ANSI_REGEX.sub("", string)
 
-    def _build_jupyter_spawn_form(self, image: JupyterImage) -> Dict[str, str]:
+    def _build_jupyter_spawn_form(self, image: JupyterImage) -> dict[str, str]:
         """Construct the form to submit to the JupyterHub login page."""
         return {
             "image_list": str(image),
diff --git a/src/mobu/models/business.py b/src/mobu/models/business.py
index 1a416e68..b8c95494 100644
--- a/src/mobu/models/business.py
+++ b/src/mobu/models/business.py
@@ -1,6 +1,6 @@
 """Models for monkey business."""
 
-from typing import List, Optional
+from typing import Optional
 
 from pydantic import BaseModel, Field
 
@@ -187,7 +187,7 @@ class BusinessData(BaseModel):
 
     success_count: int = Field(..., title="Number of successes", example=25)
 
-    timings: List[StopwatchData] = Field(..., title="Timings of events")
+    timings: list[StopwatchData] = Field(..., title="Timings of events")
 
     image: Optional[JupyterImage] = Field(
         None,
diff --git a/src/mobu/models/flock.py b/src/mobu/models/flock.py
index a509057e..ec80c95d 100644
--- a/src/mobu/models/flock.py
+++ b/src/mobu/models/flock.py
@@ -1,7 +1,7 @@
 """Models for a collection of monkeys."""
 
 from datetime import datetime
-from typing import Any, Dict, List, Literal, Optional
+from typing import Any, Literal, Optional
 
 from pydantic import BaseModel, Field, validator
 
@@ -21,7 +21,7 @@ class FlockConfig(BaseModel):
 
     count: int = Field(..., title="How many monkeys to run", example=100)
 
-    users: Optional[List[User]] = Field(
+    users: Optional[list[User]] = Field(
         None,
         title="Explicit list of users to run as",
         description=(
@@ -37,7 +37,7 @@ class FlockConfig(BaseModel):
         description="Specify either this or users but not both",
     )
 
-    scopes: List[str] = Field(
+    scopes: list[str] = Field(
         ...,
         title="Token scopes",
         description="Must include all scopes required to run the business",
@@ -63,8 +63,8 @@ class FlockConfig(BaseModel):
 
     @validator("users")
     def _valid_users(
-        cls, v: Optional[List[User]], values: Dict[str, Any]
-    ) -> Optional[List[User]]:
+        cls, v: list[User] | None, values: dict[str, Any]
+    ) -> list[User] | None:
         if v is None:
             return v
         if "count" in values and len(v) != values["count"]:
@@ -74,8 +74,8 @@ def _valid_users(
 
     @validator("user_spec", always=True)
     def _valid_user_spec(
-        cls, v: Optional[UserSpec], values: Dict[str, Any]
-    ) -> Optional[UserSpec]:
+        cls, v: UserSpec | None, values: dict[str, Any]
+    ) -> UserSpec | None:
         if v is None and ("users" not in values or values["users"] is None):
             raise ValueError("one of users or user_spec must be provided")
         if v and "users" in values and values["users"]:
@@ -99,7 +99,7 @@ class FlockData(BaseModel):
 
     config: FlockConfig = Field(..., title="Configuration for the flock")
 
-    monkeys: List[MonkeyData] = Field(..., title="Monkeys of the flock")
+    monkeys: list[MonkeyData] = Field(..., title="Monkeys of the flock")
 
 
 class FlockSummary(BaseModel):
diff --git a/src/mobu/models/jupyter.py b/src/mobu/models/jupyter.py
index ae830a6c..ba6b510d 100644
--- a/src/mobu/models/jupyter.py
+++ b/src/mobu/models/jupyter.py
@@ -1,7 +1,9 @@
 """Models for configuring a Jupyter lab."""
 
+from __future__ import annotations
+
 from enum import Enum
-from typing import Dict, Optional
+from typing import Optional, Self
 
 from pydantic import BaseModel, Field, validator
 
@@ -45,15 +47,15 @@ def __str__(self) -> str:
         return "|".join([self.reference, self.name, self.digest or ""])
 
     @classmethod
-    def from_dict(cls, data: Dict[str, str]) -> "JupyterImage":
-        return JupyterImage(
+    def from_dict(cls, data: dict[str, str]) -> Self:
+        return cls(
             reference=data["image_url"],
             name=data["name"],
             digest=data["image_hash"],
         )
 
     @classmethod
-    def from_reference(cls, reference: str) -> "JupyterImage":
+    def from_reference(cls, reference: str) -> Self:
         return cls(
             reference=reference, name=reference.rsplit(":", 1)[1], digest=""
         )
@@ -90,8 +92,8 @@ class JupyterConfig(BaseModel):
 
     @validator("image_reference")
     def _valid_image_reference(
-        cls, v: Optional[str], values: Dict[str, object]
-    ) -> Optional[str]:
+        cls, v: str | None, values: dict[str, object]
+    ) -> str | None:
         if values.get("image_class") == JupyterImageClass.BY_REFERENCE:
             if not v:
                 raise ValueError("image_reference required")
diff --git a/src/mobu/models/timings.py b/src/mobu/models/timings.py
index 046d29f1..3de9fee1 100644
--- a/src/mobu/models/timings.py
+++ b/src/mobu/models/timings.py
@@ -1,7 +1,7 @@
 """Models for timing data."""
 
 from datetime import datetime
-from typing import Dict, Optional
+from typing import Optional
 
 from pydantic import BaseModel, Field
 
@@ -11,7 +11,7 @@ class StopwatchData(BaseModel):
 
     event: str = Field(..., title="Name of the event", example="lab_create")
 
-    annotations: Dict[str, str] = Field(
+    annotations: dict[str, str] = Field(
         default_factory=dict,
         title="Event annotations",
         example={"notebook": "example.ipynb"},
diff --git a/src/mobu/models/user.py b/src/mobu/models/user.py
index 966bce77..3c0db9ae 100644
--- a/src/mobu/models/user.py
+++ b/src/mobu/models/user.py
@@ -1,7 +1,9 @@
 """Data models for an authenticated user."""
 
+from __future__ import annotations
+
 import time
-from typing import Any, List, Optional
+from typing import Any, Optional, Self
 
 from aiohttp import ClientSession
 from pydantic import BaseModel, Field
@@ -77,7 +79,7 @@ class UserSpec(BaseModel):
 class AuthenticatedUser(User):
     """Represents an authenticated user with a token."""
 
-    scopes: List[str] = Field(
+    scopes: list[str] = Field(
         ...,
         title="Token scopes",
         example=["exec:notebook", "read:tap"],
@@ -91,8 +93,8 @@ class AuthenticatedUser(User):
 
     @classmethod
     async def create(
-        cls, user: User, scopes: List[str], session: ClientSession
-    ) -> "AuthenticatedUser":
+        cls, user: User, scopes: list[str], session: ClientSession
+    ) -> Self:
         token_url = f"{config.environment_url}/auth/api/v1/tokens"
         data: dict[str, Any] = {
             "username": user.username,
diff --git a/src/mobu/monkey.py b/src/mobu/monkey.py
index 5c54419d..ba87cf92 100644
--- a/src/mobu/monkey.py
+++ b/src/mobu/monkey.py
@@ -5,7 +5,7 @@
 import logging
 import sys
 from tempfile import NamedTemporaryFile
-from typing import Optional, Type
+from typing import Optional
 
 import structlog
 from aiohttp import ClientSession
@@ -31,7 +31,7 @@ class Monkey:
     def __init__(
         self,
         monkey_config: MonkeyConfig,
-        business_type: Type[Business],
+        business_type: type[Business],
         user: AuthenticatedUser,
         session: ClientSession,
     ):
diff --git a/src/mobu/timings.py b/src/mobu/timings.py
index 0f2bf460..649e5437 100644
--- a/src/mobu/timings.py
+++ b/src/mobu/timings.py
@@ -4,7 +4,7 @@
 
 from datetime import datetime, timedelta, timezone
 from types import TracebackType
-from typing import Dict, List, Literal, Optional
+from typing import Literal, Optional
 
 from .exceptions import MobuSlackException
 from .models.timings import StopwatchData
@@ -19,10 +19,10 @@ class Timings:
 
     def __init__(self) -> None:
         self._last: Optional[Stopwatch] = None
-        self._stopwatches: List[Stopwatch] = []
+        self._stopwatches: list[Stopwatch] = []
 
     def start(
-        self, event: str, annotations: Optional[Dict[str, str]] = None
+        self, event: str, annotations: Optional[dict[str, str]] = None
     ) -> Stopwatch:
         """Start a stopwatch.
 
@@ -42,7 +42,7 @@ def start(
         self._last = stopwatch
         return stopwatch
 
-    def dump(self) -> List[StopwatchData]:
+    def dump(self) -> list[StopwatchData]:
         """Convert the stored timings to a dictionary."""
         return [s.dump() for s in self._stopwatches]
 
@@ -68,7 +68,7 @@ class Stopwatch:
     def __init__(
         self,
         event: str,
-        annotations: Dict[str, str],
+        annotations: dict[str, str],
         previous: Optional[Stopwatch] = None,
     ) -> None:
         self.event = event
@@ -83,9 +83,9 @@ def __enter__(self) -> Stopwatch:
 
     def __exit__(
         self,
-        exc_type: Optional[type],
-        exc_val: Optional[Exception],
-        exc_tb: Optional[TracebackType],
+        exc_type: type | None,
+        exc_val: Exception | None,
+        exc_tb: TracebackType | None,
     ) -> Literal[False]:
         self.stop_time = datetime.now(tz=timezone.utc)
         if exc_val:
diff --git a/src/mobu/util.py b/src/mobu/util.py
index 3e40b649..6397c912 100644
--- a/src/mobu/util.py
+++ b/src/mobu/util.py
@@ -4,7 +4,8 @@
 
 import asyncio
 from asyncio import Task
-from typing import Awaitable, Callable, Coroutine, Optional, TypeVar
+from collections.abc import Awaitable, Callable, Coroutine
+from typing import TypeVar
 
 T = TypeVar("T")
 
@@ -24,7 +25,7 @@ async def loop() -> None:
     return asyncio.ensure_future(loop())
 
 
-async def wait_first(*args: Coroutine[None, None, T]) -> Optional[T]:
+async def wait_first(*args: Coroutine[None, None, T]) -> T | None:
     """Return the result of the first awaitable to finish.
 
     The other awaitables will be cancelled.  The first awaitable determines
diff --git a/src/monkeyflocker/cli.py b/src/monkeyflocker/cli.py
index dbc84a16..7e5b6aea 100644
--- a/src/monkeyflocker/cli.py
+++ b/src/monkeyflocker/cli.py
@@ -3,7 +3,6 @@
 from __future__ import annotations
 
 from pathlib import Path
-from typing import Optional, Union
 
 import click
 from safir.asyncio import run_with_asyncio
@@ -24,7 +23,7 @@ def main() -> None:
 @main.command()
 @click.argument("topic", default=None, required=False, nargs=1)
 @click.pass_context
-def help(ctx: click.Context, topic: Union[None, str]) -> None:
+def help(ctx: click.Context, topic: str | None) -> None:
     """Show help for any command."""
     # The help command implementation is taken from
     # https://www.burgundywall.com/post/having-click-help-subcommand
@@ -124,7 +123,7 @@ async def report(base_url: str, token: str, output: Path, name: str) -> None:
 @click.argument("name")
 @run_with_asyncio
 async def stop(
-    base_url: str, token: str, output: Optional[Path], name: str
+    base_url: str, token: str, output: Path | None, name: str
 ) -> None:
     """Stop a flock."""
     async with MonkeyflockerClient(base_url, token) as client:
diff --git a/src/monkeyflocker/client.py b/src/monkeyflocker/client.py
index b4acb627..b2e216a6 100644
--- a/src/monkeyflocker/client.py
+++ b/src/monkeyflocker/client.py
@@ -7,7 +7,7 @@
 import sys
 from pathlib import Path
 from types import TracebackType
-from typing import Literal, Optional
+from typing import Literal
 from urllib.parse import urljoin
 
 import aiohttp
@@ -47,9 +47,9 @@ async def __aenter__(self) -> MonkeyflockerClient:
 
     async def __aexit__(
         self,
-        exc_type: Optional[type],
-        exc_val: Optional[Exception],
-        exc_tb: Optional[TracebackType],
+        exc_type: type | None,
+        exc_val: Exception | None,
+        exc_tb: TracebackType | None,
     ) -> Literal[False]:
         await self.aclose()
         return False
diff --git a/tests/autostart_test.py b/tests/autostart_test.py
index e5ae2210..b6338176 100644
--- a/tests/autostart_test.py
+++ b/tests/autostart_test.py
@@ -2,8 +2,8 @@
 
 from __future__ import annotations
 
+from collections.abc import Iterator
 from pathlib import Path
-from typing import Iterator
 from unittest.mock import ANY
 
 import pytest
diff --git a/tests/conftest.py b/tests/conftest.py
index d972592a..5252f189 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -2,7 +2,8 @@
 
 from __future__ import annotations
 
-from typing import Any, AsyncIterator, Iterator
+from collections.abc import AsyncIterator, Iterator
+from typing import Any
 from unittest.mock import patch
 
 import pytest
diff --git a/tests/handlers/flock_test.py b/tests/handlers/flock_test.py
index dfe5ea77..12fedfc8 100644
--- a/tests/handlers/flock_test.py
+++ b/tests/handlers/flock_test.py
@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-from typing import Any, Dict
+from typing import Any
 from unittest.mock import ANY
 
 import pytest
@@ -28,7 +28,7 @@ async def test_start_stop(
     }
     r = await client.put("/mobu/flocks", json=config)
     assert r.status_code == 201
-    expected: Dict[str, Any] = {
+    expected: dict[str, Any] = {
         "name": "test",
         "config": {
             "name": "test",
@@ -152,7 +152,7 @@ async def test_user_list(
     }
     r = await client.put("/mobu/flocks", json=config)
     assert r.status_code == 201
-    expected: Dict[str, Any] = {
+    expected: dict[str, Any] = {
         "name": "test",
         "config": config,
         "monkeys": [
diff --git a/tests/monkeyflocker_test.py b/tests/monkeyflocker_test.py
index 7a1b10a2..777b209a 100644
--- a/tests/monkeyflocker_test.py
+++ b/tests/monkeyflocker_test.py
@@ -10,8 +10,9 @@
 import socket
 import subprocess
 import time
+from collections.abc import Iterator
 from pathlib import Path
-from typing import Any, Dict, Iterator
+from typing import Any
 from unittest.mock import ANY
 
 import httpx
@@ -22,7 +23,7 @@
 from monkeyflocker.cli import main
 
 APP_SOURCE = """
-from typing import Awaitable, Callable
+from collections.abc import Awaitable, Callable
 
 from aioresponses import aioresponses
 from fastapi import FastAPI, Request, Response
@@ -151,7 +152,7 @@ def test_start_report_stop(tmp_path: Path, app_url: str) -> None:
     print(result.stdout)
     assert result.exit_code == 0
 
-    expected: Dict[str, Any] = {
+    expected: dict[str, Any] = {
         "name": "basic",
         "config": {
             "name": "basic",
diff --git a/tests/support/jupyter.py b/tests/support/jupyter.py
index 01a8ba1f..6d0d2e02 100644
--- a/tests/support/jupyter.py
+++ b/tests/support/jupyter.py
@@ -12,7 +12,7 @@
 from io import StringIO
 from re import Pattern
 from traceback import format_exc
-from typing import Any, Dict, Optional, Union
+from typing import Any, Optional
 from unittest.mock import ANY, AsyncMock, Mock
 from uuid import uuid4
 
@@ -47,7 +47,7 @@ class JupyterState(Enum):
     LAB_RUNNING = "lab running"
 
 
-def _url(route: str, regex: bool = False) -> Union[str, Pattern[str]]:
+def _url(route: str, regex: bool = False) -> str | Pattern[str]:
     """Construct a URL for JupyterHub/Proxy."""
     if not regex:
         return f"{config.environment_url}/nb/{route}"
@@ -64,13 +64,13 @@ class MockJupyter:
     """
 
     def __init__(self) -> None:
-        self.sessions: Dict[str, JupyterLabSession] = {}
-        self.state: Dict[str, JupyterState] = {}
+        self.sessions: dict[str, JupyterLabSession] = {}
+        self.state: dict[str, JupyterState] = {}
         self.delete_immediate = True
         self.spawn_timeout = False
         self.redirect_loop = False
-        self._delete_at: Dict[str, Optional[datetime]] = {}
-        self._fail: Dict[str, Dict[JupyterAction, bool]] = {}
+        self._delete_at: dict[str, datetime | None] = {}
+        self._fail: dict[str, dict[JupyterAction, bool]] = {}
 
     def fail(self, user: str, action: JupyterAction) -> None:
         """Configure the given action to fail for the given user."""
@@ -264,11 +264,11 @@ def __init__(self, user: str, session_id: str) -> None:
         super().__init__(spec=ClientWebSocketResponse)
         self.user = user
         self.session_id = session_id
-        self._header: Optional[Dict[str, str]] = None
+        self._header: Optional[dict[str, str]] = None
         self._code: Optional[str] = None
-        self._state: Dict[str, Any] = {}
+        self._state: dict[str, Any] = {}
 
-    async def send_json(self, message: Dict[str, Any]) -> None:
+    async def send_json(self, message: dict[str, Any]) -> None:
         assert message == {
             "header": {
                 "username": self.user,
@@ -292,7 +292,7 @@ async def send_json(self, message: Dict[str, Any]) -> None:
         self._header = message["header"]
         self._code = message["content"]["code"]
 
-    async def receive_json(self) -> Dict[str, Any]:
+    async def receive_json(self) -> dict[str, Any]:
         assert self._header
         if self._code == _GET_NODE:
             self._code = None
diff --git a/tests/support/util.py b/tests/support/util.py
index 04c61638..9feef641 100644
--- a/tests/support/util.py
+++ b/tests/support/util.py
@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 import asyncio
-from typing import Any, Dict
+from typing import Any
 
 from httpx import AsyncClient
 
@@ -12,7 +12,7 @@
 
 async def wait_for_business(
     client: AsyncClient, username: str
-) -> Dict[str, Any]:
+) -> dict[str, Any]:
     """Wait for one loop of business to complete and return its data."""
     for _ in range(1, 10):
         await asyncio.sleep(0.5)