diff --git a/common.hpp b/common.hpp
index 94171c7..8316184 100644
--- a/common.hpp
+++ b/common.hpp
@@ -58,7 +58,8 @@
 #include <ndn-cxx/common.hpp>
 #include <ndn-cxx/interest.hpp>
 #include <ndn-cxx/data.hpp>
-#include <ndn-cxx/util/event-emitter.hpp>
+#include <ndn-cxx/util/event-emitter.hpp> // deprecated
+#include <ndn-cxx/util/signal.hpp>
 
 #include <boost/algorithm/string.hpp>
 #include <boost/asio.hpp>
@@ -94,7 +95,7 @@
 using ndn::Name;
 using ndn::Exclude;
 using ndn::Block;
-using ndn::util::EventEmitter;
+using ndn::util::EventEmitter; // deprecated
 
 namespace tlv {
 // Don't write "namespace tlv = ndn::tlv", because NFD can add other members into this namespace.
@@ -103,6 +104,7 @@
 
 namespace name = ndn::name;
 namespace time = ndn::time;
+namespace signal = ndn::util::signal;
 
 } // namespace nfd