diff --git a/audio/channel_receive.cc b/audio/channel_receive.cc
index 17cf859ed8..b9d9ab14c8 100644
--- a/audio/channel_receive.cc
+++ b/audio/channel_receive.cc
@@ -693,10 +693,20 @@ void ChannelReceive::ReceivePacket(const uint8_t* packet,
 
     const std::vector<uint32_t> csrcs(header.arrOfCSRCs,
                                       header.arrOfCSRCs + header.numCSRCs);
+    const uint8_t additional_data_bytes[8] = {
+        0,
+        0,
+        0,
+        0,
+        static_cast<uint8_t>((header.timestamp >> 24) & 0xff),
+        static_cast<uint8_t>((header.timestamp >> 16) & 0xff),
+        static_cast<uint8_t>((header.timestamp >> 8) & 0xff),
+        static_cast<uint8_t>(header.timestamp & 0xff),
+    };
     const FrameDecryptorInterface::Result decrypt_result =
         frame_decryptor_->Decrypt(
             cricket::MEDIA_TYPE_AUDIO, csrcs,
-            /*additional_data=*/nullptr,
+            /*additional_data=*/additional_data_bytes,
             rtc::ArrayView<const uint8_t>(payload, payload_data_length),
             decrypted_audio_payload);
 
diff --git a/audio/channel_send.cc b/audio/channel_send.cc
index 4a2700177b..7ebb501704 100644
--- a/audio/channel_send.cc
+++ b/audio/channel_send.cc
@@ -320,10 +320,23 @@ int32_t ChannelSend::SendRtpAudio(AudioFrameType frameType,
 
       // Encrypt the audio payload into the buffer.
       size_t bytes_written = 0;
+      const uint32_t additional_data_timestamp =
+          rtp_timestamp_without_offset + rtp_rtcp_->StartTimestamp();
+      const uint8_t additional_data_bytes[8] = {
+          0,
+          0,
+          0,
+          0,
+          static_cast<uint8_t>((additional_data_timestamp >> 24) & 0xff),
+          static_cast<uint8_t>((additional_data_timestamp >> 16) & 0xff),
+          static_cast<uint8_t>((additional_data_timestamp >> 8) & 0xff),
+          static_cast<uint8_t>(additional_data_timestamp & 0xff),
+      };
+
       int encrypt_status = frame_encryptor_->Encrypt(
           cricket::MEDIA_TYPE_AUDIO, rtp_rtcp_->SSRC(),
-          /*additional_data=*/nullptr, payload, encrypted_audio_payload,
-          &bytes_written);
+          /*additional_data=*/additional_data_bytes, payload,
+          encrypted_audio_payload, &bytes_written);
       if (encrypt_status != 0) {
         RTC_DLOG(LS_ERROR)
             << "Channel::SendData() failed encrypt audio payload: "