diff --git a/utils/payload-with-policy.h b/utils/payload-with-policy.h
index 4cfe975..7db278b 100644
--- a/utils/payload-with-policy.h
+++ b/utils/payload-with-policy.h
@@ -21,10 +21,9 @@
 #ifndef PAYLOAD_WITH_INDEX_H_
 #define PAYLOAD_WITH_INDEX_H_
 
-namespace ns3
-{
-namespace ndnSIM
-{
+namespace ns3 {
+namespace ndn {
+namespace ndnSIM {
 
 template<typename PayloadTraits,
          typename IndexTraits>
@@ -102,6 +101,7 @@
 };
 
 } // ndnSIM
+} // ndn
 } // ns3
 
 #endif // PAYLOAD_WITH_POLICY_H_