diff --git a/modules/congestion_controller/acknowledged_bitrate_estimator.cc b/modules/congestion_controller/acknowledged_bitrate_estimator.cc
index 223c4769e6..c0161ea0d9 100644
--- a/modules/congestion_controller/acknowledged_bitrate_estimator.cc
+++ b/modules/congestion_controller/acknowledged_bitrate_estimator.cc
@@ -19,7 +19,7 @@ namespace webrtc {
 
 namespace {
 bool IsInSendTimeHistory(const PacketFeedback& packet) {
-  return packet.send_time_ms >= 0;
+  return packet.send_time_ms != PacketFeedback::kNoSendTime;
 }
 }  // namespace
 
diff --git a/modules/congestion_controller/delay_based_bwe_unittest.cc b/modules/congestion_controller/delay_based_bwe_unittest.cc
index e53667b16f..250cb036a3 100644
--- a/modules/congestion_controller/delay_based_bwe_unittest.cc
+++ b/modules/congestion_controller/delay_based_bwe_unittest.cc
@@ -34,10 +34,12 @@ TEST_F(DelayBasedBweTest, NoCrashEmptyFeedback) {
 
 TEST_F(DelayBasedBweTest, NoCrashOnlyLostFeedback) {
   std::vector<PacketFeedback> packet_feedback_vector;
-  packet_feedback_vector.push_back(
-      PacketFeedback(-1, -1, 0, 1500, PacedPacketInfo()));
-  packet_feedback_vector.push_back(
-      PacketFeedback(-1, -1, 1, 1500, PacedPacketInfo()));
+  packet_feedback_vector.push_back(PacketFeedback(PacketFeedback::kNotReceived,
+                                                  PacketFeedback::kNoSendTime,
+                                                  0, 1500, PacedPacketInfo()));
+  packet_feedback_vector.push_back(PacketFeedback(PacketFeedback::kNotReceived,
+                                                  PacketFeedback::kNoSendTime,
+                                                  1, 1500, PacedPacketInfo()));
   bitrate_estimator_->IncomingPacketFeedbackVector(packet_feedback_vector,
                                                    rtc::nullopt);
 }
diff --git a/modules/congestion_controller/send_side_congestion_controller_unittest.cc b/modules/congestion_controller/send_side_congestion_controller_unittest.cc
index 71aff4a620..67d2c402c4 100644
--- a/modules/congestion_controller/send_side_congestion_controller_unittest.cc
+++ b/modules/congestion_controller/send_side_congestion_controller_unittest.cc
@@ -384,7 +384,7 @@ TEST_F(SendSideCongestionControllerTest, LongFeedbackDelays) {
 
     // Check that packets have timed out.
     for (PacketFeedback& packet : packets) {
-      packet.send_time_ms = -1;
+      packet.send_time_ms = PacketFeedback::kNoSendTime;
       packet.payload_size = 0;
       packet.pacing_info = PacedPacketInfo();
     }
diff --git a/modules/remote_bitrate_estimator/send_time_history_unittest.cc b/modules/remote_bitrate_estimator/send_time_history_unittest.cc
index bda245c03c..6f05bcf846 100644
--- a/modules/remote_bitrate_estimator/send_time_history_unittest.cc
+++ b/modules/remote_bitrate_estimator/send_time_history_unittest.cc
@@ -116,8 +116,8 @@ TEST_F(SendTimeHistoryTest, AddThenRemoveOutOfOrder) {
   }
   for (size_t i = 0; i < num_items; ++i) {
     PacketFeedback packet = sent_packets[i];
-    packet.arrival_time_ms = -1;
-    packet.send_time_ms = -1;
+    packet.arrival_time_ms = PacketFeedback::kNotReceived;
+    packet.send_time_ms = PacketFeedback::kNoSendTime;
     history_.AddAndRemoveOld(packet);
   }
   for (size_t i = 0; i < num_items; ++i)
diff --git a/modules/rtp_rtcp/include/rtp_rtcp_defines.h b/modules/rtp_rtcp/include/rtp_rtcp_defines.h
index 0c8e389c04..ad09ad3cd2 100644
--- a/modules/rtp_rtcp/include/rtp_rtcp_defines.h
+++ b/modules/rtp_rtcp/include/rtp_rtcp_defines.h
@@ -289,7 +289,7 @@ struct PacketFeedback {
   PacketFeedback(int64_t arrival_time_ms, uint16_t sequence_number)
       : PacketFeedback(-1,
                        arrival_time_ms,
-                       -1,
+                       kNoSendTime,
                        sequence_number,
                        0,
                        0,
@@ -317,8 +317,8 @@ struct PacketFeedback {
                  uint16_t remote_net_id,
                  const PacedPacketInfo& pacing_info)
       : PacketFeedback(creation_time_ms,
-                       -1,
-                       -1,
+                       kNotReceived,
+                       kNoSendTime,
                        sequence_number,
                        payload_size,
                        local_net_id,
@@ -344,6 +344,7 @@ struct PacketFeedback {
 
   static constexpr int kNotAProbe = -1;
   static constexpr int64_t kNotReceived = -1;
+  static constexpr int64_t kNoSendTime = -1;
 
   // NOTE! The variable |creation_time_ms| is not used when testing equality.
   //       This is due to |creation_time_ms| only being used by SendTimeHistory
diff --git a/rtc_tools/event_log_visualizer/analyzer.cc b/rtc_tools/event_log_visualizer/analyzer.cc
index bbbde3f4c1..21bc5808e1 100644
--- a/rtc_tools/event_log_visualizer/analyzer.cc
+++ b/rtc_tools/event_log_visualizer/analyzer.cc
@@ -1443,7 +1443,7 @@ void EventLogAnalyzer::CreateNetworkDelayFeedbackGraph(Plot* plot) {
           float x =
               static_cast<float>(clock.TimeInMicroseconds() - begin_time_) /
               1000000;
-          if (packet.send_time_ms == -1) {
+          if (packet.send_time_ms == PacketFeedback::kNoSendTime) {
             late_feedback_series.points.emplace_back(x, prev_y);
             continue;
           }