diff --git a/video/video_stream_encoder.cc b/video/video_stream_encoder.cc
index b4b5af5..ea59b0a 100644
--- a/video/video_stream_encoder.cc
+++ b/video/video_stream_encoder.cc
@@ -336,7 +336,6 @@
     }
     // Limit to configured max framerate.
     wants.max_framerate_fps = std::min(max_framerate_, wants.max_framerate_fps);
-    wants.partial_frames = true;
     return wants;
   }
 
@@ -714,24 +713,8 @@
 
 void VideoStreamEncoder::OnFrame(const VideoFrame& video_frame) {
   RTC_DCHECK_RUNS_SERIALIZED(&incoming_frame_race_checker_);
-
-  const VideoFrame::PartialFrameDescription* partial_desc =
-      video_frame.partial_frame_description();
   VideoFrame incoming_frame = video_frame;
 
-  if (video_frame.cache_buffer_for_partial_updates()) {
-    VideoFrameBuffer* input_buffer = video_frame.video_frame_buffer();
-    if (!partial_frame_assembler_.ApplyPartialUpdate(
-            input_buffer, &incoming_frame, partial_desc)) {
-      // Can't apply new image to the cached buffer because of some error.
-      // Nothing sensible to encode.
-      // Detailed error message is already logged by |ApplyPartialUpdate()|.
-      return;
-    }
-  } else {
-    partial_frame_assembler_.Reset();
-  }
-
   // Local time in webrtc time base.
   int64_t current_time_us = clock_->TimeInMicroseconds();
   int64_t current_time_ms = current_time_us / rtc::kNumMicrosecsPerMillisec;
diff --git a/video/video_stream_encoder.h b/video/video_stream_encoder.h
index 0c9cb3c..577ca5b 100644
--- a/video/video_stream_encoder.h
+++ b/video/video_stream_encoder.h
@@ -33,7 +33,6 @@
 #include "rtc_base/sequenced_task_checker.h"
 #include "rtc_base/task_queue.h"
 #include "video/overuse_frame_detector.h"
-#include "video/partial_frame_assembler.h"
 
 namespace webrtc {
 
@@ -296,9 +295,6 @@
   // the worker thread.
   std::atomic<int> pending_frame_drops_;
 
-  PartialFrameAssembler partial_frame_assembler_
-      RTC_GUARDED_BY(incoming_frame_race_checker_);
-
   // All public methods are proxied to |encoder_queue_|. It must must be
   // destroyed first to make sure no tasks are run that use other members.
   rtc::TaskQueue encoder_queue_;