diff --git a/quic/test_tools/quic_test_client.cc b/quic/test_tools/quic_test_client.cc
index 3e577a3..caeaa51 100644
--- a/quic/test_tools/quic_test_client.cc
+++ b/quic/test_tools/quic_test_client.cc
@@ -352,8 +352,7 @@
   }
 
   QuicSpdyClientSession* session = client()->client_session();
-  QuicConnection::ScopedPacketFlusher flusher(
-      session->connection(), QuicConnection::SEND_ACK_IF_PENDING);
+  QuicConnection::ScopedPacketFlusher flusher(session->connection());
   ssize_t ret = SendMessage(headers, "", /*fin=*/true, /*flush=*/false);
 
   QuicStreamId stream_id = GetNthClientInitiatedBidirectionalStreamId(