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(
diff --git a/quic/test_tools/simple_session_notifier.cc b/quic/test_tools/simple_session_notifier.cc
index 624e4f7..16c441c 100644
--- a/quic/test_tools/simple_session_notifier.cc
+++ b/quic/test_tools/simple_session_notifier.cc
@@ -283,8 +283,7 @@
 
 void SimpleSessionNotifier::RetransmitFrames(const QuicFrames& frames,
                                              TransmissionType type) {
-  QuicConnection::ScopedPacketFlusher retransmission_flusher(
-      connection_, QuicConnection::SEND_ACK_IF_QUEUED);
+  QuicConnection::ScopedPacketFlusher retransmission_flusher(connection_);
   connection_->SetTransmissionType(type);
   for (const QuicFrame& frame : frames) {
     if (frame.type == CRYPTO_FRAME) {
diff --git a/quic/test_tools/simulator/quic_endpoint.cc b/quic/test_tools/simulator/quic_endpoint.cc
index 872a9b2..ed9d5c0 100644
--- a/quic/test_tools/simulator/quic_endpoint.cc
+++ b/quic/test_tools/simulator/quic_endpoint.cc
@@ -386,8 +386,7 @@
 
 void QuicEndpoint::WriteStreamData() {
   // Instantiate a flusher which would normally be here due to QuicSession.
-  QuicConnection::ScopedPacketFlusher flusher(
-      &connection_, QuicConnection::SEND_ACK_IF_QUEUED);
+  QuicConnection::ScopedPacketFlusher flusher(&connection_);
 
   while (bytes_to_transfer_ > 0) {
     // Transfer data in chunks of size at most |kWriteChunkSize|.