--- a/src/olsr/test/olsr-header-test-suite.cc	Fri Aug 31 12:24:28 2012 +0200
+++ b/src/olsr/test/olsr-header-test-suite.cc	Sat Sep 01 20:57:21 2012 +0200
@@ -41,7 +41,7 @@
     {
       uint8_t emf = olsr::SecondsToEmf (time);
       double seconds = olsr::EmfToSeconds (emf);
-      NS_TEST_ASSERT_MSG_EQ ((seconds < 0 || fabs (seconds - time) > 0.1), false,
+      NS_TEST_ASSERT_MSG_EQ ((seconds < 0 || std::fabs (seconds - time) > 0.1), false,
                              "XXX");
     }
 }