diff --git a/modules/congestion_controller/rtp/include/send_side_congestion_controller.h b/modules/congestion_controller/rtp/include/send_side_congestion_controller.h
index 9ab19ae447..efe4d2ff47 100644
--- a/modules/congestion_controller/rtp/include/send_side_congestion_controller.h
+++ b/modules/congestion_controller/rtp/include/send_side_congestion_controller.h
@@ -158,6 +158,8 @@ class SendSideCongestionController
  private:
   void MaybeCreateControllers() RTC_RUN_ON(task_queue_);
   void MaybeRecreateControllers() RTC_RUN_ON(task_queue_);
+  void UpdateInitialConstraints(TargetRateConstraints new_contraints)
+      RTC_RUN_ON(task_queue_);
 
   void StartProcessPeriodicTasks() RTC_RUN_ON(task_queue_);
   void UpdateControllerWithTimeInterval() RTC_RUN_ON(task_queue_);
diff --git a/modules/congestion_controller/rtp/send_side_congestion_controller.cc b/modules/congestion_controller/rtp/send_side_congestion_controller.cc
index 51803da3fb..6e6bf4dc7c 100644
--- a/modules/congestion_controller/rtp/send_side_congestion_controller.cc
+++ b/modules/congestion_controller/rtp/send_side_congestion_controller.cc
@@ -419,6 +419,14 @@ void SendSideCongestionController::MaybeRecreateControllers() {
   RTC_DCHECK(controller_);
 }
 
+void SendSideCongestionController::UpdateInitialConstraints(
+    TargetRateConstraints new_contraints) {
+  if (!new_contraints.starting_rate)
+    new_contraints.starting_rate = initial_config_.constraints.starting_rate;
+  RTC_DCHECK(new_contraints.starting_rate);
+  initial_config_.constraints = new_contraints;
+}
+
 SendSideCongestionController::~SendSideCongestionController() = default;
 
 void SendSideCongestionController::RegisterPacketFeedbackObserver(
@@ -452,7 +460,7 @@ void SendSideCongestionController::SetBweBitrates(int min_bitrate_bps,
       control_handler_->PostUpdates(
           controller_->OnTargetRateConstraints(constraints));
     } else {
-      initial_config_.constraints = constraints;
+      UpdateInitialConstraints(constraints);
     }
   });
 }
@@ -490,7 +498,7 @@ void SendSideCongestionController::OnNetworkRouteChanged(
     if (controller_) {
       control_handler_->PostUpdates(controller_->OnNetworkRouteChange(msg));
     } else {
-      initial_config_.constraints = msg.constraints;
+      UpdateInitialConstraints(msg.constraints);
     }
     pacer_controller_->OnNetworkRouteChange(msg);
   });