diff --git a/mitmproxy/addons/proxyserver.py b/mitmproxy/addons/proxyserver.py
index 14fa47951..e69da4381 100644
--- a/mitmproxy/addons/proxyserver.py
+++ b/mitmproxy/addons/proxyserver.py
@@ -73,7 +73,7 @@ class Proxyserver:
         )
         yield "DNS", self.dns_server, lambda x: setattr(self, "dns_server", x), ctx.options.dns_server, lambda: udp.start_server(
             self.handle_dns_datagram,
-            self.options.dns_listen_host or '127.0.0.1',
+            self.options.dns_listen_host or "127.0.0.1",
             self.options.dns_listen_port,
             transparent=self.options.dns_mode == "transparent"
         )
@@ -237,7 +237,7 @@ class Proxyserver:
             del self._connections[connection_id]
 
     async def handle_tcp_connection(self, reader: asyncio.StreamReader, writer: asyncio.StreamWriter) -> None:
-        connection_id = ("tcp", writer.get_extra_info('peername'), writer.get_extra_info('sockname'))
+        connection_id = ("tcp", writer.get_extra_info("peername"), writer.get_extra_info("sockname"))
         self._connections[connection_id] = ProxyConnectionHandler(self.master, reader, writer, self.options)
         await self.handle_connection(connection_id)
 
@@ -301,7 +301,8 @@ class Proxyserver:
     async def server_connect(self, ctx: server_hooks.ServerConnectionHookData):
         assert ctx.server.address
 
-        addrinfos = await asyncio.get_running_loop().getaddrinfo(*ctx.server.address[:2], proto=ctx.server.protocol.value)
+        host, port = ctx.server.address[:2]
+        addrinfos = await asyncio.get_running_loop().getaddrinfo(host, port, proto=ctx.server.protocol.value)
         for srv in self.running_servers:
             for sock in srv.sockets:
                 for family, _, proto, _, addr in addrinfos:
diff --git a/mitmproxy/net/udp.py b/mitmproxy/net/udp.py
index 7c72583a1..1e06649ba 100644
--- a/mitmproxy/net/udp.py
+++ b/mitmproxy/net/udp.py
@@ -89,7 +89,7 @@ class DrainableDatagramProtocol(asyncio.DatagramProtocol):
         self._sock = None
 
     def __repr__(self) -> str:
-        return f'<{self.__class__.__name__} socket={self._sock!r}>'
+        return f"<{self.__class__.__name__} socket={self._sock!r}>"
 
     @property
     def sockets(self) -> Tuple[socket.socket, ...]:
diff --git a/test/mitmproxy/addons/test_proxyserver.py b/test/mitmproxy/addons/test_proxyserver.py
index e9b431e3b..3bc726651 100644
--- a/test/mitmproxy/addons/test_proxyserver.py
+++ b/test/mitmproxy/addons/test_proxyserver.py
@@ -234,34 +234,37 @@ async def test_dns_simple() -> None:
     flow = tdnsflow(resp=False)
     ps = Proxyserver()
     with taddons.context(ps) as tctx:
-        tctx.configure(ps, server=False, dns_server=True, dns_listen_port=5353, dns_mode="simple")
+        tctx.configure(ps, server=False, dns_server=True, dns_listen_host="127.0.0.1", dns_listen_port=0, dns_mode="simple")
         await ps.running()
         await tctx.master.await_log("DNS server listening at", level="info")
         await ps.dns_request(flow)
         assert flow.response
         await ps.shutdown_server()
+        await tctx.master.await_log("Stopping DNS server", level="info")
 
 
 async def test_dns_not_simple() -> None:
     flow = tdnsflow(resp=False)
     ps = Proxyserver()
     with taddons.context(ps) as tctx:
-        tctx.configure(ps, server=False, dns_server=True, dns_listen_port=5354, dns_mode="custom")
+        tctx.configure(ps, server=False, dns_server=True, dns_listen_host="127.0.0.1", dns_listen_port=0, dns_mode="custom")
         await ps.running()
         await tctx.master.await_log("DNS server listening at", level="info")
         await ps.dns_request(flow)
         assert not flow.response
         await ps.shutdown_server()
+        await tctx.master.await_log("Stopping DNS server", level="info")
 
 
 async def test_dns() -> None:
     ps = Proxyserver()
     with taddons.context(ps) as tctx:
-        tctx.configure(ps, server=False, dns_server=True, dns_listen_port=5355, dns_mode="simple")
+        tctx.configure(ps, server=False, dns_server=True, dns_listen_host="127.0.0.1", dns_listen_port=0, dns_mode="simple")
         await ps.running()
         await tctx.master.await_log("DNS server listening at", level="info")
         assert ps.dns_server
-        r, w = await udp.open_connection(*ps.dns_server.sockets[0].getsockname()[:2])
+        dns_addr = ps.dns_server.sockets[0].getsockname()[:2]
+        r, w = await udp.open_connection(*dns_addr)
         req = tdnsreq()
         w.write(req.packed)
         resp = dns.Message.unpack(await r.read(udp.MAX_DATAGRAM_SIZE))
@@ -273,3 +276,4 @@ async def test_dns() -> None:
         assert req.id == resp.id and "8.8.8.8" in str(resp)
         assert len(ps._connections) == 1
         await ps.shutdown_server()
+        await tctx.master.await_log("Stopping DNS server", level="info")