diff --git a/tools/chunks/catchunks/statistics-collector.cpp b/tools/chunks/catchunks/statistics-collector.cpp
index 91af79d..2e303c9 100644
--- a/tools/chunks/catchunks/statistics-collector.cpp
+++ b/tools/chunks/catchunks/statistics-collector.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2019,  Regents of the University of California,
+ * Copyright (c) 2016-2022,  Regents of the University of California,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University.
  *
@@ -24,8 +24,7 @@
 
 #include "statistics-collector.hpp"
 
-namespace ndn {
-namespace chunks {
+namespace ndn::chunks {
 
 StatisticsCollector::StatisticsCollector(PipelineInterestsAdaptive& pipeline,
                                          std::ostream& osCwnd, std::ostream& osRtt)
@@ -48,5 +47,4 @@
   });
 }
 
-} // namespace chunks
-} // namespace ndn
+} // namespace ndn::chunks