diff --git a/rsocket/transports/aioquic_transport.py b/rsocket/transports/aioquic_transport.py
index 55534f65..53230772 100644
--- a/rsocket/transports/aioquic_transport.py
+++ b/rsocket/transports/aioquic_transport.py
@@ -6,7 +6,7 @@
 from aioquic.quic.events import QuicEvent, StreamDataReceived, ConnectionTerminated
 
 from rsocket.exceptions import RSocketTransportError
-from rsocket.frame import Frame
+from rsocket.frame import Frame, serialize_with_frame_size_header
 from rsocket.helpers import wrap_transport_exception, cancel_if_task_exists
 from rsocket.logger import logger
 from rsocket.rsocket_server import RSocketServer
@@ -63,7 +63,7 @@ def __init__(self, *args, **kwargs):
         self._stream_id = self._quic.get_next_available_stream_id()
 
     async def query(self, frame: Frame) -> None:
-        data = frame.serialize()
+        data = serialize_with_frame_size_header(frame)
         self._quic.send_stream_data(self._stream_id, data, end_stream=False)
         self.transmit()
 
@@ -103,7 +103,7 @@ async def incoming_data_listener(self):
                     self._incoming_frame_queue.put_nowait(data)
                     return
                 else:
-                    async for frame in self._frame_parser.receive_data(data, 0):
+                    async for frame in self._frame_parser.receive_data(data):
                         self._incoming_frame_queue.put_nowait(frame)
 
         except asyncio.CancelledError:
@@ -116,3 +116,6 @@ async def close(self):
         self._quic_protocol.close()
 
         await self._quic_protocol.wait_closed()
+
+    def requires_length_header(self) -> bool:
+        return True
diff --git a/rsocket/transports/http3_transport.py b/rsocket/transports/http3_transport.py
index 79e24d27..3a179f3f 100644
--- a/rsocket/transports/http3_transport.py
+++ b/rsocket/transports/http3_transport.py
@@ -17,7 +17,7 @@
 from starlette.websockets import WebSocket, WebSocketDisconnect
 
 from rsocket.exceptions import RSocketTransportError
-from rsocket.frame import Frame
+from rsocket.frame import Frame, serialize_with_frame_size_header
 from rsocket.helpers import wrap_transport_exception, cancel_if_task_exists
 from rsocket.logger import logger
 from rsocket.transports.abstract_messaging import AbstractMessagingTransport
@@ -159,7 +159,8 @@ def __init__(self, websocket: Union[WebSocket, ClientWebSocket]):
     async def send_frame(self, frame: Frame):
         with wrap_transport_exception():
             try:
-                await self._websocket.send_bytes(frame.serialize())
+                data = serialize_with_frame_size_header(frame)
+                await self._websocket.send_bytes(data)
             except WebSocketDisconnect:
                 self._disconnect_event.set()
 
@@ -177,7 +178,7 @@ async def incoming_data_listener(self):
                     self._disconnect_event.set()
                     break
 
-                async for frame in self._frame_parser.receive_data(data, 0):
+                async for frame in self._frame_parser.receive_data(data):
                     self._incoming_frame_queue.put_nowait(frame)
 
         except asyncio.CancelledError:
@@ -189,3 +190,6 @@ async def incoming_data_listener(self):
 
     async def wait_for_disconnect(self):
         await self._disconnect_event.wait()
+
+    def requires_length_header(self) -> bool:
+        return True