diff --git a/quiche/quic/test_tools/quic_test_utils.cc b/quiche/quic/test_tools/quic_test_utils.cc
index e04f0ca..ecc08ac 100644
--- a/quiche/quic/test_tools/quic_test_utils.cc
+++ b/quiche/quic/test_tools/quic_test_utils.cc
@@ -455,9 +455,9 @@
 
 MockQuicConnectionHelper::~MockQuicConnectionHelper() {}
 
-const QuicClock* MockQuicConnectionHelper::GetClock() const { return &clock_; }
+const MockClock* MockQuicConnectionHelper::GetClock() const { return &clock_; }
 
-QuicClock* MockQuicConnectionHelper::GetClock() { return &clock_; }
+MockClock* MockQuicConnectionHelper::GetClock() { return &clock_; }
 
 QuicRandom* MockQuicConnectionHelper::GetRandomGenerator() {
   return &random_generator_;
@@ -551,16 +551,18 @@
   return false;
 }
 
-PacketSavingConnection::PacketSavingConnection(
-    QuicConnectionHelperInterface* helper, QuicAlarmFactory* alarm_factory,
-    Perspective perspective)
-    : MockQuicConnection(helper, alarm_factory, perspective) {}
+PacketSavingConnection::PacketSavingConnection(MockQuicConnectionHelper* helper,
+                                               QuicAlarmFactory* alarm_factory,
+                                               Perspective perspective)
+    : MockQuicConnection(helper, alarm_factory, perspective),
+      mock_helper_(helper) {}
 
 PacketSavingConnection::PacketSavingConnection(
-    QuicConnectionHelperInterface* helper, QuicAlarmFactory* alarm_factory,
+    MockQuicConnectionHelper* helper, QuicAlarmFactory* alarm_factory,
     Perspective perspective, const ParsedQuicVersionVector& supported_versions)
     : MockQuicConnection(helper, alarm_factory, perspective,
-                         supported_versions) {}
+                         supported_versions),
+      mock_helper_(helper) {}
 
 PacketSavingConnection::~PacketSavingConnection() {}
 
@@ -572,12 +574,13 @@
 void PacketSavingConnection::SendOrQueuePacket(SerializedPacket packet) {
   encrypted_packets_.push_back(std::make_unique<QuicEncryptedPacket>(
       CopyBuffer(packet), packet.encrypted_length, true));
-  clock_.AdvanceTime(QuicTime::Delta::FromMilliseconds(10));
+  MockClock& clock = *mock_helper_->GetClock();
+  clock.AdvanceTime(QuicTime::Delta::FromMilliseconds(10));
   // Transfer ownership of the packet to the SentPacketManager and the
   // ack notifier to the AckNotifierManager.
   OnPacketSent(packet.encryption_level, packet.transmission_type);
   QuicConnectionPeer::GetSentPacketManager(this)->OnPacketSent(
-      &packet, clock_.ApproximateNow(), NOT_RETRANSMISSION,
+      &packet, clock.ApproximateNow(), NOT_RETRANSMISSION,
       HAS_RETRANSMITTABLE_DATA, true, ECN_NOT_ECT);
 }
 
@@ -1132,7 +1135,7 @@
 void CreateClientSessionForTest(
     QuicServerId server_id, QuicTime::Delta connection_start_time,
     const ParsedQuicVersionVector& supported_versions,
-    QuicConnectionHelperInterface* helper, QuicAlarmFactory* alarm_factory,
+    MockQuicConnectionHelper* helper, QuicAlarmFactory* alarm_factory,
     QuicCryptoClientConfig* crypto_client_config,
     PacketSavingConnection** client_connection,
     TestQuicSpdyClientSession** client_session) {
@@ -1155,7 +1158,7 @@
 void CreateServerSessionForTest(
     QuicServerId /*server_id*/, QuicTime::Delta connection_start_time,
     ParsedQuicVersionVector supported_versions,
-    QuicConnectionHelperInterface* helper, QuicAlarmFactory* alarm_factory,
+    MockQuicConnectionHelper* helper, QuicAlarmFactory* alarm_factory,
     QuicCryptoServerConfig* server_crypto_config,
     QuicCompressedCertsCache* compressed_certs_cache,
     PacketSavingConnection** server_connection,
diff --git a/quiche/quic/test_tools/quic_test_utils.h b/quiche/quic/test_tools/quic_test_utils.h
index ab1ec88..4a054f3 100644
--- a/quiche/quic/test_tools/quic_test_utils.h
+++ b/quiche/quic/test_tools/quic_test_utils.h
@@ -516,8 +516,8 @@
   MockQuicConnectionHelper(const MockQuicConnectionHelper&) = delete;
   MockQuicConnectionHelper& operator=(const MockQuicConnectionHelper&) = delete;
   ~MockQuicConnectionHelper() override;
-  const QuicClock* GetClock() const override;
-  QuicClock* GetClock();
+  const MockClock* GetClock() const override;
+  MockClock* GetClock();
   QuicRandom* GetRandomGenerator() override;
   quiche::QuicheBufferAllocator* GetStreamSendBufferAllocator() override;
   void AdvanceTime(QuicTime::Delta delta);
@@ -737,11 +737,11 @@
 
 class PacketSavingConnection : public MockQuicConnection {
  public:
-  PacketSavingConnection(QuicConnectionHelperInterface* helper,
+  PacketSavingConnection(MockQuicConnectionHelper* helper,
                          QuicAlarmFactory* alarm_factory,
                          Perspective perspective);
 
-  PacketSavingConnection(QuicConnectionHelperInterface* helper,
+  PacketSavingConnection(MockQuicConnectionHelper* helper,
                          QuicAlarmFactory* alarm_factory,
                          Perspective perspective,
                          const ParsedQuicVersionVector& supported_versions);
@@ -761,7 +761,7 @@
   // Number of packets in encrypted_packets that has been delivered to the peer
   // connection.
   size_t number_of_packets_delivered_ = 0;
-  MockClock clock_;
+  MockQuicConnectionHelper* mock_helper_ = nullptr;
 };
 
 class MockQuicSession : public QuicSession {
@@ -1540,7 +1540,7 @@
 void CreateClientSessionForTest(
     QuicServerId server_id, QuicTime::Delta connection_start_time,
     const ParsedQuicVersionVector& supported_versions,
-    QuicConnectionHelperInterface* helper, QuicAlarmFactory* alarm_factory,
+    MockQuicConnectionHelper* helper, QuicAlarmFactory* alarm_factory,
     QuicCryptoClientConfig* crypto_client_config,
     PacketSavingConnection** client_connection,
     TestQuicSpdyClientSession** client_session);
@@ -1563,7 +1563,7 @@
 void CreateServerSessionForTest(
     QuicServerId server_id, QuicTime::Delta connection_start_time,
     ParsedQuicVersionVector supported_versions,
-    QuicConnectionHelperInterface* helper, QuicAlarmFactory* alarm_factory,
+    MockQuicConnectionHelper* helper, QuicAlarmFactory* alarm_factory,
     QuicCryptoServerConfig* server_crypto_config,
     QuicCompressedCertsCache* compressed_certs_cache,
     PacketSavingConnection** server_connection,