diff --git a/tools/nfdc/execute-command.cpp b/tools/nfdc/execute-command.cpp
index 7067ebf..6706ffc 100644
--- a/tools/nfdc/execute-command.cpp
+++ b/tools/nfdc/execute-command.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2019,  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,
@@ -25,9 +25,7 @@
 
 #include "execute-command.hpp"
 
-namespace nfd {
-namespace tools {
-namespace nfdc {
+namespace nfd::tools::nfdc {
 
 time::nanoseconds
 ExecuteContext::getTimeout() const
@@ -60,6 +58,4 @@
   };
 }
 
-} // namespace nfdc
-} // namespace tools
-} // namespace nfd
+} // namespace nfd::tools::nfdc