diff --git a/samples/ns-2/simple.tcl.cc b/samples/ns-2/simple.tcl.cc
index 67543b5e0..f0b23a1de 100644
--- a/samples/ns-2/simple.tcl.cc
+++ b/samples/ns-2/simple.tcl.cc
@@ -22,6 +22,7 @@
 // replacement ns-3 code, to highlight the change in design
 
 #include "ns3/simulator.h"
+#include "ns3/nstime.h"
 
 using namespace ns3;
 
@@ -92,7 +93,7 @@ int main (int argc, char *argv[])
     // puts [$cbr0 set interval_]
     // 
     // $ns at 3.0 "finish"
-    // Simulator::StopAt (3.0);
+    Simulator::StopAt (Seconds(3.0));
     // 
     // proc finish {} {
     //         global ns f nf