diff --git a/src/simulator/simulator.h b/src/simulator/simulator.h
index da15eabc2..7c02acaae 100644
--- a/src/simulator/simulator.h
+++ b/src/simulator/simulator.h
@@ -321,6 +321,10 @@ private:
 }; // namespace ns3
 
 
+/********************************************************************
+     Implementation of templates defined above
+ ********************************************************************/
+
 namespace ns3 {
 
 template <typename T>