diff --git a/matrix_alertbot/alertmanager.py b/matrix_alertbot/alertmanager.py
index eb55a15..b2caa5b 100644
--- a/matrix_alertbot/alertmanager.py
+++ b/matrix_alertbot/alertmanager.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import datetime
 from typing import Any, Dict, List
 
@@ -20,6 +22,9 @@ class AlertmanagerClient(AsyncContextManager):
         self.cache = cache
         self.session = aiohttp.ClientSession()
 
+    def __aenter__(self) -> AlertmanagerClient:
+        return self
+
     async def __aexit__(self, *args: Any, **kwargs: Any) -> None:
         await super().__aexit__(*args, **kwargs)
         await self.close()
diff --git a/matrix_alertbot/main.py b/matrix_alertbot/main.py
index b75514c..a35c2a3 100644
--- a/matrix_alertbot/main.py
+++ b/matrix_alertbot/main.py
@@ -5,6 +5,7 @@ import sys
 from asyncio import TimeoutError
 from time import sleep
 
+import aiotools
 from aiohttp import ClientConnectionError, ServerDisconnectedError
 from diskcache import Cache
 from nio import (
@@ -52,7 +53,7 @@ def create_matrix_client(config: Config) -> AsyncClient:
 
 
 async def start_matrix_client(cache: Cache, config: Config) -> bool:
-    async with create_matrix_client(config) as client:
+    async with aiotools.closing_async(create_matrix_client(config)) as client:
         # Configure Alertmanager client
         async with AlertmanagerClient(config.alertmanager_url, cache) as alertmanager:
             # Set up event callbacks
@@ -114,9 +115,9 @@ async def start_matrix_client(cache: Cache, config: Config) -> bool:
 
 
 async def start_webhook_server(cache: Cache, config: Config) -> None:
-    async with create_matrix_client(config) as client:
-        webhook_server = Webhook(client, cache, config)
-        await webhook_server.start()
+    async with aiotools.closing_async(create_matrix_client(config)) as client:
+        async with Webhook(client, cache, config) as webhook_server:
+            await webhook_server.start()
 
 
 def main() -> None:
diff --git a/matrix_alertbot/webhook.py b/matrix_alertbot/webhook.py
index b2b353c..f2254e4 100644
--- a/matrix_alertbot/webhook.py
+++ b/matrix_alertbot/webhook.py
@@ -1,6 +1,10 @@
+from __future__ import annotations
+
 import logging
+from typing import Any
 
 from aiohttp import web, web_request
+from aiotools import AsyncContextManager
 from diskcache import Cache
 from nio import AsyncClient, SendRetryError
 
@@ -47,7 +51,7 @@ async def create_alert(request: web_request.Request) -> web.Response:
     return web.Response(status=200)
 
 
-class Webhook:
+class Webhook(AsyncContextManager):
     def __init__(self, client: AsyncClient, cache: Cache, config: Config) -> None:
         self.app = web.Application(logger=logger)
         self.app["client"] = client
@@ -61,6 +65,13 @@ class Webhook:
         self.port = config.port
         self.socket = config.socket
 
+    def __aenter__(self) -> Webhook:
+        return self
+
+    async def __aexit__(self, *args: Any, **kwargs: Any) -> None:
+        await super().__aexit__(*args, **kwargs)
+        await self.close()
+
     async def start(self) -> None:
         await self.runner.setup()