diff --git a/python/lsst/daf/butler/remote_butler/server/handlers/_external_query.py b/python/lsst/daf/butler/remote_butler/server/handlers/_external_query.py
index 3b5f627b61..e24a9b808f 100644
--- a/python/lsst/daf/butler/remote_butler/server/handlers/_external_query.py
+++ b/python/lsst/daf/butler/remote_butler/server/handlers/_external_query.py
@@ -129,7 +129,7 @@ async def _stream_query_pages(
     # exit_stack.
     async with contextmanager_in_threadpool(exit_stack):
         # `None` signals that there is no more data to send.
-        queue = asyncio.Queue[QueryExecuteResultData | None](1)
+        queue = asyncio.Queue[QueryExecuteResultData | None](2)
         async with asyncio.TaskGroup() as tg:
             tg.create_task(_enqueue_query_pages(ctx, spec, queue))
             async for message in _dequeue_query_pages_with_keepalive(queue):