diff --git a/kopf/_kits/webhooks.py b/kopf/_kits/webhooks.py
index 0884fad0..5c165b52 100644
--- a/kopf/_kits/webhooks.py
+++ b/kopf/_kits/webhooks.py
@@ -165,7 +165,8 @@ async def _serve_fn(request: aiohttp.web.Request) -> aiohttp.web.Response:
             # multi-threaded sockets are not really used -- high load is not expected for webhooks.
             addr = self.addr or None  # None is aiohttp's "any interface"
             port = self.port or self._allocate_free_port()
-            site = aiohttp.web.TCPSite(runner, addr, port, ssl_context=context, reuse_port=True)
+            site = aiohttp.web.TCPSite(runner, addr, port, ssl_context=context, reuse_port=True,
+                                       shutdown_timeout=0.0001)
             await site.start()
 
             # Log with the actual URL: normalised, with hostname/port set.
diff --git a/setup.py b/setup.py
index 5533d6b2..245a1299 100644
--- a/setup.py
+++ b/setup.py
@@ -62,7 +62,7 @@
         'python-json-logger',   # 0.05 MB
         'iso8601',              # 0.07 MB
         'click',                # 0.60 MB
-        'aiohttp<4.0.0',        # 7.80 MB
+        'aiohttp==3.9.0b0',        # 7.80 MB
         'pyyaml',               # 0.90 MB
     ],
     extras_require={