diff --git a/modules/video_coding/utility/quality_scaler_unittest.cc b/modules/video_coding/utility/quality_scaler_unittest.cc
index d5b22a8a29..d92cffc5bf 100644
--- a/modules/video_coding/utility/quality_scaler_unittest.cc
+++ b/modules/video_coding/utility/quality_scaler_unittest.cc
@@ -115,8 +115,7 @@ INSTANTIATE_TEST_SUITE_P(
     FieldTrials,
     QualityScalerTest,
     ::testing::Values(
-        "WebRTC-Video-QualityScaling/Enabled-1,2,3,4,5,6,7,8,0.9,0.99,1/",
-        ""));
+        "WebRTC-Video-QualityScaling/Enabled-1,2,3,4,5,6,7,8,0.9,0.99,1/"));
 
 TEST_P(QualityScalerTest, DownscalesAfterContinuousFramedrop) {
   task_queue_.SendTask([this] { TriggerScale(kScaleDown); }, RTC_FROM_HERE);
diff --git a/rtc_base/experiments/quality_scaling_experiment.cc b/rtc_base/experiments/quality_scaling_experiment.cc
index ca58ba858a..64347fe9f5 100644
--- a/rtc_base/experiments/quality_scaling_experiment.cc
+++ b/rtc_base/experiments/quality_scaling_experiment.cc
@@ -19,6 +19,8 @@
 namespace webrtc {
 namespace {
 constexpr char kFieldTrial[] = "WebRTC-Video-QualityScaling";
+constexpr char kDefaultQualityScalingSetttings[] =
+    "Enabled-29,95,149,205,24,37,26,36,0.9995,0.9999,1";
 constexpr int kMinQp = 1;
 constexpr int kMaxVp8Qp = 127;
 constexpr int kMaxVp9Qp = 255;
@@ -38,14 +40,16 @@ absl::optional<VideoEncoder::QpThresholds> GetThresholds(int low,
 }  // namespace
 
 bool QualityScalingExperiment::Enabled() {
-  return webrtc::field_trial::IsEnabled(kFieldTrial);
+  return !webrtc::field_trial::IsDisabled(kFieldTrial);
 }
 
 absl::optional<QualityScalingExperiment::Settings>
 QualityScalingExperiment::ParseSettings() {
-  const std::string group = webrtc::field_trial::FindFullName(kFieldTrial);
+  std::string group = webrtc::field_trial::FindFullName(kFieldTrial);
+  // TODO(http:crbug.org/webrtc/12401): Completely remove the experiment code
+  // after few releases.
   if (group.empty())
-    return absl::nullopt;
+    group = kDefaultQualityScalingSetttings;
 
   Settings s;
   if (sscanf(group.c_str(), "Enabled-%d,%d,%d,%d,%d,%d,%d,%d,%f,%f,%d",
diff --git a/rtc_base/experiments/quality_scaling_experiment_unittest.cc b/rtc_base/experiments/quality_scaling_experiment_unittest.cc
index 7a345b629f..2ecdd7c49e 100644
--- a/rtc_base/experiments/quality_scaling_experiment_unittest.cc
+++ b/rtc_base/experiments/quality_scaling_experiment_unittest.cc
@@ -38,9 +38,9 @@ void ExpectEqualConfig(QualityScalingExperiment::Config a,
 }
 }  // namespace
 
-TEST(QualityScalingExperimentTest, DisabledWithoutFieldTrial) {
+TEST(QualityScalingExperimentTest, DefaultEnabledWithoutFieldTrial) {
   webrtc::test::ScopedFieldTrials field_trials("");
-  EXPECT_FALSE(QualityScalingExperiment::Enabled());
+  EXPECT_TRUE(QualityScalingExperiment::Enabled());
 }
 
 TEST(QualityScalingExperimentTest, EnabledWithFieldTrial) {
@@ -59,9 +59,10 @@ TEST(QualityScalingExperimentTest, ParseSettings) {
   ExpectEqualSettings(kExpected, *settings);
 }
 
-TEST(QualityScalingExperimentTest, ParseSettingsFailsWithoutFieldTrial) {
+TEST(QualityScalingExperimentTest, ParseSettingsUsesDefaultsWithoutFieldTrial) {
   webrtc::test::ScopedFieldTrials field_trials("");
-  EXPECT_FALSE(QualityScalingExperiment::ParseSettings());
+  // Uses some default hard coded values.
+  EXPECT_TRUE(QualityScalingExperiment::ParseSettings());
 }
 
 TEST(QualityScalingExperimentTest, ParseSettingsFailsWithInvalidFieldTrial) {
diff --git a/video/video_stream_encoder_unittest.cc b/video/video_stream_encoder_unittest.cc
index aed1625f9e..8220daa465 100644
--- a/video/video_stream_encoder_unittest.cc
+++ b/video/video_stream_encoder_unittest.cc
@@ -5517,6 +5517,8 @@ TEST_F(VideoStreamEncoderTest, RampsUpInQualityWhenBwIsHigh) {
 
 TEST_F(VideoStreamEncoderTest,
        QualityScalerAdaptationsRemovedWhenQualityScalingDisabled) {
+  webrtc::test::ScopedFieldTrials field_trials(
+      "WebRTC-Video-QualityScaling/Disabled/");
   AdaptingFrameForwarder source(&time_controller_);
   source.set_adaptation_enabled(true);
   video_stream_encoder_->SetSource(&source,