diff --git a/utils/trie-with-policy.h b/utils/trie-with-policy.h
index 12168ea..8afa6f8 100644
--- a/utils/trie-with-policy.h
+++ b/utils/trie-with-policy.h
@@ -23,10 +23,9 @@
 
 #include "trie.h"
 
-namespace ns3
-{
-namespace ndnSIM
-{
+namespace ns3 {
+namespace ndn {
+namespace ndnSIM {
 
 template<typename FullKey,
          typename PayloadTraits,
@@ -236,6 +235,7 @@
 };
 
 } // ndnSIM
+} // ndn
 } // ns3
 
 #endif // TRIE_WITH_POLICY_H_