diff --git a/src/internet/test/tcp-general-test.cc b/src/internet/test/tcp-general-test.cc
index 3f1c4cbab..794467696 100644
--- a/src/internet/test/tcp-general-test.cc
+++ b/src/internet/test/tcp-general-test.cc
@@ -193,6 +193,8 @@ TcpGeneralTest::DoRun (void)
                                               MakeCallback (&TcpGeneralTest::RxPacketCb, this));
   m_senderSocket->TraceConnectWithoutContext ("RTT",
                                               MakeCallback (&TcpGeneralTest::RttTrace, this));
+  m_senderSocket->TraceConnectWithoutContext ("BytesInFlight",
+                                              MakeCallback (&TcpGeneralTest::BytesInFlightTrace, this));
 
   m_remoteAddr = InetSocketAddress (serverAddress, 4477);
 
diff --git a/src/internet/test/tcp-general-test.h b/src/internet/test/tcp-general-test.h
index ac32d4e07..9e805a52a 100644
--- a/src/internet/test/tcp-general-test.h
+++ b/src/internet/test/tcp-general-test.h
@@ -503,6 +503,18 @@ protected:
   {
   }
 
+  /**
+   * \brief Bytes in flight changes
+   *
+   * This applies only for sender socket.
+   *
+   * \param oldValue old value
+   * \param newValue new value
+   */
+  virtual void BytesInFlightTrace (uint32_t oldValue, uint32_t newValue)
+  {
+  }
+
   /**
    * \brief Socket closed normally
    * \param who the socket closed (SENDER or RECEIVER)