diff --git a/rtc_tools/network_tester/config_reader.cc b/rtc_tools/network_tester/config_reader.cc
index 7e01a6577e..a0ee29355a 100644
--- a/rtc_tools/network_tester/config_reader.cc
+++ b/rtc_tools/network_tester/config_reader.cc
@@ -32,7 +32,7 @@ ConfigReader::~ConfigReader() = default;
 rtc::Optional<ConfigReader::Config> ConfigReader::GetNextConfig() {
 #ifdef WEBRTC_NETWORK_TESTER_PROTO
   if (proto_config_index_ >= proto_all_configs_.configs_size())
-    return rtc::Optional<Config>();
+    return rtc::nullopt;
   auto proto_config = proto_all_configs_.configs(proto_config_index_++);
   RTC_DCHECK(proto_config.has_packet_send_interval_ms());
   RTC_DCHECK(proto_config.has_packet_size());
@@ -41,9 +41,9 @@ rtc::Optional<ConfigReader::Config> ConfigReader::GetNextConfig() {
   config.packet_send_interval_ms = proto_config.packet_send_interval_ms();
   config.packet_size = proto_config.packet_size();
   config.execution_time_ms = proto_config.execution_time_ms();
-  return rtc::Optional<Config>(config);
+  return config;
 #else
-  return rtc::Optional<Config>();
+  return rtc::nullopt;
 #endif  //  WEBRTC_NETWORK_TESTER_PROTO
 }
 
diff --git a/rtc_tools/network_tester/packet_sender.cc b/rtc_tools/network_tester/packet_sender.cc
index 3b252524dd..2c38b2fc4d 100644
--- a/rtc_tools/network_tester/packet_sender.cc
+++ b/rtc_tools/network_tester/packet_sender.cc
@@ -115,7 +115,7 @@ void PacketSender::SendPacket() {
   packet.set_type(NetworkTesterPacket::TEST_DATA);
   packet.set_sequence_number(sequence_number_++);
   packet.set_send_timestamp(rtc::TimeMicros());
-  test_controller_->SendData(packet, rtc::Optional<size_t>(packet_size_));
+  test_controller_->SendData(packet, packet_size_);
 }
 
 int64_t PacketSender::GetSendIntervalMs() const {
diff --git a/rtc_tools/network_tester/test_controller.cc b/rtc_tools/network_tester/test_controller.cc
index 908e6954ce..ea03c87486 100644
--- a/rtc_tools/network_tester/test_controller.cc
+++ b/rtc_tools/network_tester/test_controller.cc
@@ -37,7 +37,7 @@ void TestController::SendConnectTo(const std::string& hostname, int port) {
   udp_transport_->SetRemoteAddress(rtc::SocketAddress(hostname, port));
   NetworkTesterPacket packet;
   packet.set_type(NetworkTesterPacket::HAND_SHAKING);
-  SendData(packet, rtc::Optional<size_t>());
+  SendData(packet, rtc::nullopt);
   rtc::CritScope scoped_lock(&local_test_done_lock_);
   local_test_done_ = false;
   remote_test_done_ = false;
@@ -65,7 +65,7 @@ void TestController::OnTestDone() {
   RTC_DCHECK_CALLED_SEQUENTIALLY(&packet_sender_checker_);
   NetworkTesterPacket packet;
   packet.set_type(NetworkTesterPacket::TEST_DONE);
-  SendData(packet, rtc::Optional<size_t>());
+  SendData(packet, rtc::nullopt);
   rtc::CritScope scoped_lock(&local_test_done_lock_);
   local_test_done_ = true;
 }
@@ -92,7 +92,7 @@ void TestController::OnReadPacket(rtc::AsyncPacketSocket* socket,
       NetworkTesterPacket packet;
       packet.set_type(NetworkTesterPacket::TEST_START);
       udp_transport_->SetRemoteAddress(remote_addr);
-      SendData(packet, rtc::Optional<size_t>());
+      SendData(packet, rtc::nullopt);
       packet_sender_.reset(new PacketSender(this, config_file_path_));
       packet_sender_->StartSending();
       rtc::CritScope scoped_lock(&local_test_done_lock_);