diff --git a/src/route/fib.hpp b/src/route/fib.hpp
index e24c61b..1a9b75f 100644
--- a/src/route/fib.hpp
+++ b/src/route/fib.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2022,  The University of Memphis,
+ * Copyright (c) 2014-2023,  The University of Memphis,
  *                           Regents of the University of California,
  *                           Arizona Board of Regents.
  *
@@ -222,7 +222,7 @@
   static inline const ndn::Name MULTICAST_STRATEGY{"/localhost/nfd/strategy/multicast"};
   static inline const ndn::Name BEST_ROUTE_STRATEGY{"/localhost/nfd/strategy/best-route"};
 
-  ndn::util::Signal<Fib, ndn::Name> onPrefixRegistrationSuccess;
+  ndn::signal::Signal<Fib, ndn::Name> onPrefixRegistrationSuccess;
 
 private:
   ndn::Scheduler& m_scheduler;
diff --git a/src/route/name-prefix-table.hpp b/src/route/name-prefix-table.hpp
index 449b928..5ac8345 100644
--- a/src/route/name-prefix-table.hpp
+++ b/src/route/name-prefix-table.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2021,  The University of Memphis,
+ * Copyright (c) 2014-2023,  The University of Memphis,
  *                           Regents of the University of California,
  *                           Arizona Board of Regents.
  *
@@ -141,8 +141,8 @@
   const ndn::Name& m_ownRouterName;
   Fib& m_fib;
   RoutingTable& m_routingTable;
-  ndn::util::signal::Connection m_afterRoutingChangeConnection;
-  ndn::util::signal::Connection m_afterLsdbModified;
+  ndn::signal::Connection m_afterRoutingChangeConnection;
+  ndn::signal::Connection m_afterLsdbModified;
 };
 
 inline NamePrefixTable::const_iterator
diff --git a/src/route/routing-table.hpp b/src/route/routing-table.hpp
index f7e0525..c49eaec 100644
--- a/src/route/routing-table.hpp
+++ b/src/route/routing-table.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2021,  The University of Memphis,
+ * Copyright (c) 2014-2023,  The University of Memphis,
  *                           Regents of the University of California
  *
  * This file is part of NLSR (Named-data Link State Routing).
@@ -155,7 +155,7 @@
   bool m_isRouteCalculationScheduled;
 
   ConfParameter& m_confParam;
-  ndn::util::signal::Connection m_afterLsdbModified;
+  ndn::signal::Connection m_afterLsdbModified;
   int32_t m_hyperbolicState;
   bool m_ownAdjLsaExist = false;
 };