diff --git a/tools/nfdc/available-commands.hpp b/tools/nfdc/available-commands.hpp
index a887eec..ad6525c 100644
--- a/tools/nfdc/available-commands.hpp
+++ b/tools/nfdc/available-commands.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2014-2016,  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,
@@ -28,15 +28,11 @@
 
 #include "command-parser.hpp"
 
-namespace nfd {
-namespace tools {
-namespace nfdc {
+namespace nfd::tools::nfdc {
 
 void
 registerCommands(CommandParser& parser);
 
-} // namespace nfdc
-} // namespace tools
-} // namespace nfd
+} // namespace nfd::tools::nfdc
 
 #endif // NFD_TOOLS_NFDC_AVAILABLE_COMMANDS_HPP