diff --git a/quic/test_tools/quic_connection_peer.cc b/quic/test_tools/quic_connection_peer.cc
index ef2ffb3..8b99730 100644
--- a/quic/test_tools/quic_connection_peer.cc
+++ b/quic/test_tools/quic_connection_peer.cc
@@ -226,6 +226,9 @@
 // static
 QuicPacketCount QuicConnectionPeer::GetPacketsBetweenMtuProbes(
     QuicConnection* connection) {
+  if (connection->mtu_discovery_v2_) {
+    return connection->mtu_discoverer_.packets_between_probes();
+  }
   return connection->packets_between_mtu_probes_;
 }
 
@@ -242,6 +245,15 @@
 }
 
 // static
+void QuicConnectionPeer::ReInitializeMtuDiscoverer(
+    QuicConnection* connection,
+    QuicPacketCount packets_between_probes_base,
+    QuicPacketNumber next_probe_at) {
+  connection->mtu_discoverer_ =
+      QuicConnectionMtuDiscoverer(packets_between_probes_base, next_probe_at);
+}
+
+// static
 void QuicConnectionPeer::SetAckMode(QuicConnection* connection,
                                     AckMode ack_mode) {
   for (auto& received_packet_manager :
diff --git a/quic/test_tools/quic_connection_peer.h b/quic/test_tools/quic_connection_peer.h
index f329a1c..5b97ae6 100644
--- a/quic/test_tools/quic_connection_peer.h
+++ b/quic/test_tools/quic_connection_peer.h
@@ -111,6 +111,10 @@
                                          QuicPacketCount packets);
   static void SetNextMtuProbeAt(QuicConnection* connection,
                                 QuicPacketNumber number);
+  static void ReInitializeMtuDiscoverer(
+      QuicConnection* connection,
+      QuicPacketCount packets_between_probes_base,
+      QuicPacketNumber next_probe_at);
   static void SetAckMode(QuicConnection* connection, AckMode ack_mode);
   static void SetFastAckAfterQuiescence(QuicConnection* connection,
                                         bool fast_ack_after_quiescence);
diff --git a/quic/test_tools/quic_test_utils.h b/quic/test_tools/quic_test_utils.h
index fbadf13..1cd2683 100644
--- a/quic/test_tools/quic_test_utils.h
+++ b/quic/test_tools/quic_test_utils.h
@@ -1258,6 +1258,10 @@
   return arg.destination_connection_id == destination_connection_id;
 }
 
+MATCHER_P2(InRange, min, max, "") {
+  return arg >= min && arg <= max;
+}
+
 }  // namespace test
 }  // namespace quic