diff --git a/webrtc/logging/rtc_event_log/rtc_event_log_unittest.cc b/webrtc/logging/rtc_event_log/rtc_event_log_unittest.cc
index 07b394a556..0a13be3a30 100644
--- a/webrtc/logging/rtc_event_log/rtc_event_log_unittest.cc
+++ b/webrtc/logging/rtc_event_log/rtc_event_log_unittest.cc
@@ -126,7 +126,7 @@ RtpPacketToSend GenerateRtpPacket(const RtpHeaderExtensionMap* extensions,
 
   rtp_packet.SetExtension<TransmissionOffset>(prng->Rand(0x00ffffff));
   rtp_packet.SetExtension<AudioLevel>(prng->Rand<bool>(), prng->Rand(127));
-  rtp_packet.SetExtension<AbsoluteSendTime>(prng->Rand<int32_t>());
+  rtp_packet.SetExtension<AbsoluteSendTime>(prng->Rand(0x00ffffff));
   rtp_packet.SetExtension<VideoOrientation>(prng->Rand(2));
   rtp_packet.SetExtension<TransportSequenceNumber>(prng->Rand<uint16_t>());
 
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.cc b/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.cc
index 3bb9bc5553..2f3feb34cd 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.cc
+++ b/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.cc
@@ -43,8 +43,9 @@ bool AbsoluteSendTime::Parse(rtc::ArrayView<const uint8_t> data,
   return true;
 }
 
-bool AbsoluteSendTime::Write(uint8_t* data, int64_t time_ms) {
-  ByteWriter<uint32_t, 3>::WriteBigEndian(data, MsTo24Bits(time_ms));
+bool AbsoluteSendTime::Write(uint8_t* data, uint32_t time_24bits) {
+  RTC_DCHECK_LE(time_24bits, 0x00FFFFFF);
+  ByteWriter<uint32_t, 3>::WriteBigEndian(data, time_24bits);
   return true;
 }
 
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h b/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h
index a1f69dd0f9..d3e72ebd22 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h
+++ b/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h
@@ -28,8 +28,8 @@ class AbsoluteSendTime {
       "http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time";
 
   static bool Parse(rtc::ArrayView<const uint8_t> data, uint32_t* time_24bits);
-  static size_t ValueSize(int64_t time_ms) { return kValueSizeBytes; }
-  static bool Write(uint8_t* data, int64_t time_ms);
+  static size_t ValueSize(uint32_t time_24bits) { return kValueSizeBytes; }
+  static bool Write(uint8_t* data, uint32_t time_24bits);
 
   static constexpr uint32_t MsTo24Bits(int64_t time_ms) {
     return static_cast<uint32_t>(((time_ms << 18) + 500) / 1000) & 0x00FFFFFF;
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_sender.cc b/webrtc/modules/rtp_rtcp/source/rtp_sender.cc
index 1bdb804e82..00edd18f3f 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_sender.cc
+++ b/webrtc/modules/rtp_rtcp/source/rtp_sender.cc
@@ -559,7 +559,8 @@ size_t RTPSender::SendPadData(size_t bytes,
       padding_packet.SetExtension<TransmissionOffset>(
           (now_ms - capture_time_ms) * kTimestampTicksPerMs);
     }
-    padding_packet.SetExtension<AbsoluteSendTime>(now_ms);
+    padding_packet.SetExtension<AbsoluteSendTime>(
+        AbsoluteSendTime::MsTo24Bits(now_ms));
     PacketOptions options;
     bool has_transport_seq_num =
         UpdateTransportSequenceNumber(&padding_packet, &options.packet_id);
@@ -739,7 +740,8 @@ bool RTPSender::PrepareAndSendPacket(std::unique_ptr<RtpPacketToSend> packet,
   int64_t diff_ms = now_ms - capture_time_ms;
   packet_to_send->SetExtension<TransmissionOffset>(kTimestampTicksPerMs *
                                                    diff_ms);
-  packet_to_send->SetExtension<AbsoluteSendTime>(now_ms);
+  packet_to_send->SetExtension<AbsoluteSendTime>(
+      AbsoluteSendTime::MsTo24Bits(now_ms));
 
   PacketOptions options;
   if (UpdateTransportSequenceNumber(packet_to_send, &options.packet_id)) {
@@ -829,7 +831,7 @@ bool RTPSender::SendToNetwork(std::unique_ptr<RtpPacketToSend> packet,
     packet->SetExtension<TransmissionOffset>(
         kTimestampTicksPerMs * (now_ms - packet->capture_time_ms()));
   }
-  packet->SetExtension<AbsoluteSendTime>(now_ms);
+  packet->SetExtension<AbsoluteSendTime>(AbsoluteSendTime::MsTo24Bits(now_ms));
 
   if (video_) {
     BWE_TEST_LOGGING_PLOT_WITH_SSRC(1, "VideoTotBitrate_kbps", now_ms,