diff --git a/video/encoder_bitrate_adjuster.cc b/video/encoder_bitrate_adjuster.cc
index ae25527427..8743099ae3 100644
--- a/video/encoder_bitrate_adjuster.cc
+++ b/video/encoder_bitrate_adjuster.cc
@@ -51,7 +51,7 @@ EncoderBitrateAdjuster::EncoderBitrateAdjuster(
     Clock& clock)
     : utilize_bandwidth_headroom_(RateControlSettings(field_trials)
                                       .BitrateAdjusterCanUseNetworkHeadroom()),
-      use_newfangled_headroom_adjustment_(field_trials.IsEnabled(
+      use_newfangled_headroom_adjustment_(!field_trials.IsDisabled(
           "WebRTC-BitrateAdjusterUseNewfangledHeadroomAdjustment")),
       frames_since_layout_change_(0),
       min_bitrates_bps_{},
diff --git a/video/rate_utilization_tracker.cc b/video/rate_utilization_tracker.cc
index 373493c1f0..9403ff13b4 100644
--- a/video/rate_utilization_tracker.cc
+++ b/video/rate_utilization_tracker.cc
@@ -91,7 +91,9 @@ absl::optional<double> RateUtilizationTracker::GetRateUtilizationFactor(
 
     if (update.produced_data.IsZero()) {
       // Just a rate update past the last seen produced data.
-      data_allocated_for_last_data += allocated_since_previous_data_point;
+      data_allocated_for_last_data =
+          std::min(size_of_last_data, data_allocated_for_last_data +
+                                          allocated_since_previous_data_point);
     } else {
       // A newer data point with produced data, reset accumulator for rate
       // allocated past the last data point.
diff --git a/video/rate_utilization_tracker_unittest.cc b/video/rate_utilization_tracker_unittest.cc
index 33efbdd619..2e75d66a7b 100644
--- a/video/rate_utilization_tracker_unittest.cc
+++ b/video/rate_utilization_tracker_unittest.cc
@@ -248,5 +248,22 @@ TEST(RateUtilizationTrackerTest, EqualTimestampsTreatedAtSameDataPoint) {
       PrettyCloseTo(3.0 / 4.0));
 }
 
+TEST(RateUtilizationTrackerTest, FullRateAfterLastDataPoint) {
+  RateUtilizationTracker tracker(kDefaultMaxDataPoints, kDefaultTimeWindow);
+  constexpr TimeDelta kFrameInterval = TimeDelta::Seconds(1) / 33;
+  constexpr DataRate kTargetRate = DataRate::KilobitsPerSec(100);
+  constexpr DataSize kIdealFrameSize = kTargetRate * kFrameInterval;
+
+  tracker.OnDataRateChanged(kTargetRate, kStartTime);
+  tracker.OnDataProduced(kIdealFrameSize, kStartTime);
+
+  // New rate update, but accumulated rate for last data point fully saturated
+  // by next to last rate update.
+  tracker.OnDataRateChanged(kTargetRate, kStartTime + kFrameInterval * 2);
+
+  EXPECT_THAT(tracker.GetRateUtilizationFactor(kStartTime + kFrameInterval * 3),
+              PrettyCloseTo(1.0 / 3.0));
+}
+
 }  // namespace
 }  // namespace webrtc