diff --git a/test/configurable_frame_size_encoder.cc b/test/configurable_frame_size_encoder.cc
index f037b9824d..071845f24a 100644
--- a/test/configurable_frame_size_encoder.cc
+++ b/test/configurable_frame_size_encoder.cc
@@ -54,7 +54,9 @@ int32_t ConfigurableFrameSizeEncoder::Encode(
   CodecSpecificInfo specific{};
   specific.codecType = codec_type_;
   callback_->OnEncodedImage(encodedImage, &specific, fragmentation);
-
+  if (post_encode_callback_) {
+    (*post_encode_callback_)();
+  }
   return WEBRTC_VIDEO_CODEC_OK;
 }
 
@@ -89,5 +91,10 @@ void ConfigurableFrameSizeEncoder::SetCodecType(VideoCodecType codec_type) {
   codec_type_ = codec_type;
 }
 
+void ConfigurableFrameSizeEncoder::RegisterPostEncodeCallback(
+    std::function<void(void)> post_encode_callback) {
+  post_encode_callback_ = std::move(post_encode_callback);
+}
+
 }  // namespace test
 }  // namespace webrtc
diff --git a/test/configurable_frame_size_encoder.h b/test/configurable_frame_size_encoder.h
index 1dc9e48f47..03dc149018 100644
--- a/test/configurable_frame_size_encoder.h
+++ b/test/configurable_frame_size_encoder.h
@@ -46,8 +46,13 @@ class ConfigurableFrameSizeEncoder : public VideoEncoder {
 
   void SetCodecType(VideoCodecType codec_type_);
 
+  void RegisterPostEncodeCallback(
+      std::function<void(void)> post_encode_callback);
+
  private:
   EncodedImageCallback* callback_;
+  absl::optional<std::function<void(void)>> post_encode_callback_;
+
   const size_t max_frame_size_;
   size_t current_frame_size_;
   std::unique_ptr<uint8_t[]> buffer_;
diff --git a/video/video_send_stream_tests.cc b/video/video_send_stream_tests.cc
index 0e3ca72186..76bd227f1b 100644
--- a/video/video_send_stream_tests.cc
+++ b/video/video_send_stream_tests.cc
@@ -17,7 +17,6 @@
 #include "call/fake_network_pipe.h"
 #include "call/rtp_transport_controller_send.h"
 #include "call/simulated_network.h"
-#include "common_video/include/frame_callback.h"
 #include "modules/rtp_rtcp/include/rtp_header_parser.h"
 #include "modules/rtp_rtcp/include/rtp_rtcp.h"
 #include "modules/rtp_rtcp/source/rtcp_sender.h"
@@ -964,8 +963,7 @@ void VideoSendStreamTest::TestPacketFragmentationSize(VideoFormat format,
 
   // Observer that verifies that the expected number of packets and bytes
   // arrive for each frame size, from start_size to stop_size.
-  class FrameFragmentationTest : public test::SendTest,
-                                 public EncodedFrameObserver {
+  class FrameFragmentationTest : public test::SendTest {
    public:
     FrameFragmentationTest(size_t max_packet_size,
                            size_t start_size,
@@ -1101,7 +1099,7 @@ void VideoSendStreamTest::TestPacketFragmentationSize(VideoFormat format,
       }
     }
 
-    void EncodedFrameCallback(const EncodedFrame& encoded_frame) override {
+    void UpdateConfiguration() {
       rtc::CritScope lock(&mutex_);
       // Increase frame size for next encoded frame, in the context of the
       // encoder thread.
@@ -1132,7 +1130,7 @@ void VideoSendStreamTest::TestPacketFragmentationSize(VideoFormat format,
 
       send_config->encoder_settings.encoder_factory = &encoder_factory_;
       send_config->rtp.max_packet_size = kMaxPacketSize;
-      send_config->post_encode_callback = this;
+      encoder_.RegisterPostEncodeCallback([this]() { UpdateConfiguration(); });
 
       // Make sure there is at least one extension header, to make the RTP
       // header larger than the base length of 12 bytes.