diff --git a/examples/ndn-csma.cpp b/examples/ndn-csma.cpp
index 71d1cfb..7a08f79 100644
--- a/examples/ndn-csma.cpp
+++ b/examples/ndn-csma.cpp
@@ -17,13 +17,15 @@
  *
  * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
  */
+
 // ndn-csma.cc
+
 #include "ns3/core-module.h"
 #include "ns3/network-module.h"
 #include "ns3/csma-module.h"
 #include "ns3/ndnSIM-module.h"
 
-using namespace ns3;
+namespace ns3 {
 
 /**
  * This scenario simulates a very simple network topology:
@@ -96,3 +98,11 @@
 
   return 0;
 }
+
+} // namespace ns3
+
+int
+main(int argc, char* argv[])
+{
+  return ns3::main(argc, argv);
+}