diff --git a/call/fake_network_pipe.cc b/call/fake_network_pipe.cc
index 492eae2eb5..19a6ddc43a 100644
--- a/call/fake_network_pipe.cc
+++ b/call/fake_network_pipe.cc
@@ -117,6 +117,7 @@ FakeNetworkPipe::FakeNetworkPipe(Clock* clock,
       receiver_(nullptr),
       transport_(nullptr),
       random_(seed),
+      clock_offset_ms_(0),
       config_(),
       dropped_packets_(0),
       sent_packets_(0),
@@ -134,6 +135,7 @@ FakeNetworkPipe::FakeNetworkPipe(Clock* clock,
       receiver_(nullptr),
       transport_(transport),
       random_(1),
+      clock_offset_ms_(0),
       config_(),
       dropped_packets_(0),
       sent_packets_(0),
@@ -179,6 +181,11 @@ PacketReceiver::DeliveryStatus FakeNetworkPipe::DeliverPacket(
              : PacketReceiver::DELIVERY_PACKET_ERROR;
 }
 
+void FakeNetworkPipe::SetClockOffset(int64_t offset_ms) {
+  rtc::CritScope crit(&config_lock_);
+  clock_offset_ms_ = offset_ms;
+}
+
 void FakeNetworkPipe::SetConfig(const FakeNetworkPipe::Config& config) {
   rtc::CritScope crit(&config_lock_);
   config_ = config;  // Shallow copy of the struct.
@@ -394,6 +401,7 @@ void FakeNetworkPipe::DeliverPacket(NetworkPacket* packet) {
       int64_t queue_time = packet->arrival_time() - packet->send_time();
       RTC_CHECK(queue_time >= 0);
       packet_time.timestamp += (queue_time * 1000);
+      packet_time.timestamp += (clock_offset_ms_ * 1000);
     }
     receiver_->DeliverPacket(packet->media_type(),
                              std::move(*packet->raw_packet()), packet_time);
diff --git a/call/fake_network_pipe.h b/call/fake_network_pipe.h
index bd3a79c8d7..3c6cfdd6b1 100644
--- a/call/fake_network_pipe.h
+++ b/call/fake_network_pipe.h
@@ -149,6 +149,8 @@ class FakeNetworkPipe : public Transport, public PacketReceiver, public Module {
 
   virtual ~FakeNetworkPipe();
 
+  void SetClockOffset(int64_t offset_ms);
+
   // Sets a new configuration. This won't affect packets already in the pipe.
   void SetConfig(const FakeNetworkPipe::Config& config);
 
@@ -229,6 +231,8 @@ class FakeNetworkPipe : public Transport, public PacketReceiver, public Module {
 
   std::deque<NetworkPacket> delay_link_;
 
+  int64_t clock_offset_ms_ RTC_GUARDED_BY(config_lock_);
+
   // Link configuration.
   Config config_ RTC_GUARDED_BY(config_lock_);
 
diff --git a/test/direct_transport.cc b/test/direct_transport.cc
index dddbe58909..971130fe9e 100644
--- a/test/direct_transport.cc
+++ b/test/direct_transport.cc
@@ -68,6 +68,10 @@ DirectTransport::~DirectTransport() {
   task_queue_->CancelTask(next_scheduled_task_);
 }
 
+void DirectTransport::SetClockOffset(int64_t offset_ms) {
+  fake_network_->SetClockOffset(offset_ms);
+}
+
 void DirectTransport::SetConfig(const FakeNetworkPipe::Config& config) {
   fake_network_->SetConfig(config);
 }
diff --git a/test/direct_transport.h b/test/direct_transport.h
index 2a59096889..d61282aae7 100644
--- a/test/direct_transport.h
+++ b/test/direct_transport.h
@@ -51,6 +51,8 @@ class DirectTransport : public Transport {
 
   ~DirectTransport() override;
 
+  void SetClockOffset(int64_t offset_ms);
+
   void SetConfig(const FakeNetworkPipe::Config& config);
 
   RTC_DEPRECATED void StopSending();