diff --git a/tests/daemon/rib-io-fixture.hpp b/tests/daemon/rib-io-fixture.hpp
index f8660fd..73a43bc 100644
--- a/tests/daemon/rib-io-fixture.hpp
+++ b/tests/daemon/rib-io-fixture.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2020,  Regents of the University of California,
+ * Copyright (c) 2014-2022,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -32,8 +32,7 @@
 #include <mutex>
 #include <thread>
 
-namespace nfd {
-namespace tests {
+namespace nfd::tests {
 
 /** \brief A base test fixture that provides both main and RIB io_service.
  */
@@ -86,7 +85,6 @@
   afterTick() final;
 };
 
-} // namespace tests
-} // namespace nfd
+} // namespace nfd::tests
 
 #endif // NFD_TESTS_DAEMON_RIB_IO_FIXTURE_HPP