diff --git a/conformance/test/client.py b/conformance/test/client.py
index b27a601..8e89524 100644
--- a/conformance/test/client.py
+++ b/conformance/test/client.py
@@ -125,6 +125,8 @@ def pyqwest_client_kwargs(test_request: ClientCompatRequest) -> dict:
             kwargs["http_version"] = PyQwestHTTPVersion.HTTP1
         case HTTPVersion.HTTP_VERSION_2:
             kwargs["http_version"] = PyQwestHTTPVersion.HTTP2
+        case HTTPVersion.HTTP_VERSION_3:
+            kwargs["http_version"] = PyQwestHTTPVersion.HTTP3
     if test_request.server_tls_cert:
         kwargs["tls_ca_cert"] = test_request.server_tls_cert
         if test_request.HasField("client_tls_creds"):
diff --git a/conformance/test/config.yaml b/conformance/test/config.yaml
index 91d2cc2..6c6225f 100644
--- a/conformance/test/config.yaml
+++ b/conformance/test/config.yaml
@@ -2,6 +2,7 @@ features:
   versions:
     - HTTP_VERSION_1
     - HTTP_VERSION_2
+    - HTTP_VERSION_3
   protocols:
     - PROTOCOL_CONNECT
     - PROTOCOL_GRPC
diff --git a/conformance/test/server.py b/conformance/test/server.py
index c7ecbd9..ef39ecc 100644
--- a/conformance/test/server.py
+++ b/conformance/test/server.py
@@ -2,6 +2,7 @@
 
 import argparse
 import asyncio
+import contextlib
 import os
 import re
 import signal
@@ -10,6 +11,7 @@
 import sys
 import time
 from contextlib import ExitStack, closing
+from pathlib import Path
 from tempfile import NamedTemporaryFile
 from typing import TYPE_CHECKING, Literal, TypeVar, get_args
 
@@ -17,6 +19,7 @@
 import _cov_embed  # noqa: F401
 from _util import create_standard_streams
 from gen.connectrpc.conformance.v1.config_pb2 import Code as ConformanceCode
+from gen.connectrpc.conformance.v1.config_pb2 import HTTPVersion
 from gen.connectrpc.conformance.v1.server_compat_pb2 import (
     ServerCompatRequest,
     ServerCompatResponse,
@@ -43,6 +46,7 @@
     UnaryResponseDefinition,
 )
 from google.protobuf.any_pb2 import Any
+from pyvoy import PyvoyServer
 
 from connectrpc.code import Code
 from connectrpc.compression.brotli import BrotliCompression
@@ -635,40 +639,47 @@ async def serve_pyvoy(
     cafile: str | None,
     port_future: asyncio.Future[int],
 ):
-    args = ["--port=0"]
-    if certfile:
-        args.append(f"--tls-cert={certfile}")
-    if keyfile:
-        args.append(f"--tls-key={keyfile}")
-    if cafile:
-        args.append(f"--tls-ca-cert={cafile}")
+    tls_cert = Path(certfile) if certfile else None
+    tls_key = Path(keyfile) if keyfile else None
+    tls_ca_cert = Path(cafile) if cafile else None
+    tls_port = 0 if tls_key else None
 
     if mode == "sync":
-        args.append("--interface=wsgi")
-        args.append("server:wsgi_app")
+        interface = "wsgi"
+        app = "server:wsgi_app"
     else:
-        args.append("server:asgi_app")
-
-    proc = await asyncio.create_subprocess_exec(
-        "pyvoy",
-        *args,
-        stderr=asyncio.subprocess.STDOUT,
-        stdout=asyncio.subprocess.PIPE,
-        env=_server_env(request),
-    )
-    stdout = proc.stdout
-    assert stdout is not None
-    stdout = _tee_to_stderr(stdout)
+        interface = "asgi"
+        app = "server:asgi_app"
+
+    async def start():
+        # Currently explicit env not accepted but it's safe to set it here.
+        os.environ["READ_MAX_BYTES"] = str(request.message_receive_limit)
+        async with PyvoyServer(
+            app,
+            port=0,
+            tls_port=tls_port,
+            interface=interface,
+            tls_key=tls_key,
+            tls_cert=tls_cert,
+            tls_ca_cert=tls_ca_cert,
+        ) as server:
+            if (
+                request.http_version == HTTPVersion.HTTP_VERSION_3
+                and server.listener_port_quic
+            ):
+                port = server.listener_port_quic
+            else:
+                port = server.listener_port_tls or server.listener_port
+            port_future.set_result(port)
+            await asyncio.Future()  # run until cancelled
+
+    task = asyncio.create_task(start())
     try:
-        async for line in stdout:
-            if b"listening on" in line:
-                port = int(line.strip().split(b"127.0.0.1:")[1])
-                port_future.set_result(port)
-                break
-        await _consume_log(stdout)
+        await task
     except asyncio.CancelledError:
-        proc.terminate()
-        await proc.wait()
+        task.cancel()
+        with contextlib.suppress(asyncio.CancelledError):
+            await task
 
 
 async def serve_uvicorn(
diff --git a/conformance/test/test_server.py b/conformance/test/test_server.py
index 4670593..a38ac35 100644
--- a/conformance/test/test_server.py
+++ b/conformance/test/test_server.py
@@ -51,8 +51,8 @@ def test_server_sync(server: str, cov: Coverage) -> None:
     opts = []
     match server:
         case "gunicorn":
-            # gunicorn doesn't support HTTP/2
-            opts = ["--skip", "**/HTTPVersion:2/**"]
+            # gunicorn doesn't support HTTP/2 or 3
+            opts = ["--skip", "**/HTTPVersion:2/**", "--skip", "**/HTTPVersion:3/**"]
 
     result = subprocess.run(
         [
@@ -89,6 +89,9 @@ def test_server_async(server: str, cov: Coverage) -> None:
                 # daphne doesn't support h2c
                 "--skip",
                 "**/HTTPVersion:2/**/TLS:false/**",
+                # daphne doesn't support HTTP/3
+                "--skip",
+                "**/HTTPVersion:3/**",
                 # daphne seems to block on the request body so can't do full duplex even with h2,
                 # it only works with websockets
                 "--skip",
@@ -102,8 +105,8 @@ def test_server_async(server: str, cov: Coverage) -> None:
                 "gRPC Unexpected Requests/**",
             ]
         case "uvicorn":
-            # uvicorn doesn't support HTTP/2
-            opts = ["--skip", "**/HTTPVersion:2/**"]
+            # uvicorn doesn't support HTTP/2 or 3
+            opts = ["--skip", "**/HTTPVersion:2/**", "--skip", "**/HTTPVersion:3/**"]
     result = subprocess.run(
         [
             "go",