diff --git a/src/detail/ndncert-common.cpp b/src/detail/ndncert-common.cpp
index 7c210b7..5e22afb 100644
--- a/src/detail/ndncert-common.cpp
+++ b/src/detail/ndncert-common.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -20,7 +20,6 @@
 
 #include "detail/ndncert-common.hpp"
 
-namespace ndn {
 namespace ndncert {
 
 std::ostream&
@@ -56,4 +55,3 @@
 }
 
 } // namespace ndncert
-} // namespace ndn