diff --git a/src/detail/info-encoder.hpp b/src/detail/info-encoder.hpp
index 4eaa967..e4a9cab 100644
--- a/src/detail/info-encoder.hpp
+++ b/src/detail/info-encoder.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2017-2021, Regents of the University of California.
+ * Copyright (c) 2017-2022, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,8 +23,7 @@
 
 #include "detail/ca-profile.hpp"
 
-namespace ndncert {
-namespace infotlv {
+namespace ndncert::infotlv {
 
 /**
  * Encode CA configuration and its certificate into a TLV block as INFO Data packet content.
@@ -38,7 +37,6 @@
 CaProfile
 decodeDataContent(const Block& block);
 
-} // namespace infotlv
-} // namespace ndncert
+} // namespace ndncert::infotlv
 
 #endif // NDNCERT_DETAIL_INFO_ENCODER_HPP