diff -r 9ebf12703683 src/core/test/threaded-test-suite.cc
--- a/src/core/test/threaded-test-suite.cc	Tue Apr 03 18:59:41 2012 +0200
+++ b/src/core/test/threaded-test-suite.cc	Sun Apr 08 19:41:02 2012 +0200
@@ -232,7 +232,9 @@
     : TestSuite ("threaded-simulator")
   {
     std::string simulatorTypes[] = {
+#ifdef HAVE_RT
       "ns3::RealtimeSimulatorImpl",
+#endif /* HAVE_RT */
       "ns3::DefaultSimulatorImpl"
     };
     std::string schedulerTypes[] = {