diff --git a/openair1/PHY/TOOLS/time_meas.h b/openair1/PHY/TOOLS/time_meas.h
index 2ab8430740..b4f7bfc0be 100644
--- a/openair1/PHY/TOOLS/time_meas.h
+++ b/openair1/PHY/TOOLS/time_meas.h
@@ -30,6 +30,7 @@
 #include <omp.h>
 #endif
 #include <unistd.h>
+#include <math.h>
 // global var to enable openair performance profiler 
 extern int opp_enabled;