diff --git a/tests/unit/util/signal.t.cpp b/tests/unit/util/signal.t.cpp
index b3640f9..001d02a 100644
--- a/tests/unit/util/signal.t.cpp
+++ b/tests/unit/util/signal.t.cpp
@@ -25,10 +25,9 @@
 
 #include <boost/concept_check.hpp>
 
-namespace ndn {
-namespace util {
-namespace signal {
-namespace tests {
+namespace ndn::tests {
+
+using namespace ndn::signal;
 
 BOOST_AUTO_TEST_SUITE(Util)
 BOOST_AUTO_TEST_SUITE(TestSignal)
@@ -477,7 +476,4 @@
 BOOST_AUTO_TEST_SUITE_END() // TestSignal
 BOOST_AUTO_TEST_SUITE_END() // Util
 
-} // namespace tests
-} // namespace signal
-} // namespace util
-} // namespace ndn
+} // namespace ndn::tests