diff --git a/api/frame_transformer_interface.h b/api/frame_transformer_interface.h
index 2f7b139..bfe3b02 100644
--- a/api/frame_transformer_interface.h
+++ b/api/frame_transformer_interface.h
@@ -72,6 +72,7 @@
   // information in the header as needed, for example to compile the list of
   // csrcs.
   virtual const RTPHeader& GetHeader() const = 0;
+  virtual void SetRTPTimestamp(uint32_t timestamp) { RTC_CHECK_NOTREACHED(); }
 
   virtual rtc::ArrayView<const uint32_t> GetContributingSources() const = 0;
 };
diff --git a/api/test/mock_transformable_audio_frame.h b/api/test/mock_transformable_audio_frame.h
index 7a31ecd..c8d24f0 100644
--- a/api/test/mock_transformable_audio_frame.h
+++ b/api/test/mock_transformable_audio_frame.h
@@ -24,6 +24,7 @@
   MOCK_METHOD(uint32_t, GetSsrc, (), (const, override));
   MOCK_METHOD(uint32_t, GetTimestamp, (), (const, override));
   MOCK_METHOD(RTPHeader&, GetHeader, (), (const override));
+  MOCK_METHOD(void, SetRTPTimestamp, (uint32_t), (override));
   MOCK_METHOD(rtc::ArrayView<const uint32_t>,
               GetContributingSources,
               (),
diff --git a/audio/channel_receive_frame_transformer_delegate.cc b/audio/channel_receive_frame_transformer_delegate.cc
index e8ba6de..1cb08f0 100644
--- a/audio/channel_receive_frame_transformer_delegate.cc
+++ b/audio/channel_receive_frame_transformer_delegate.cc
@@ -33,6 +33,10 @@
     payload_.SetData(data.data(), data.size());
   }
 
+  void SetRTPTimestamp(uint32_t timestamp) override {
+    header_.timestamp = timestamp;
+  }
+
   uint8_t GetPayloadType() const override { return header_.payloadType; }
   uint32_t GetSsrc() const override { return ssrc_; }
   uint32_t GetTimestamp() const override { return header_.timestamp; }