--- lib/signal_op.cpp.orig	Wed Apr 19 17:26:21 2017
+++ lib/signal_op.cpp	Wed Apr 19 17:26:25 2017
@@ -13,6 +13,7 @@
 
 
 #include <math.h>
+#include <cstdlib>
 #include "signal_op.h"
 #include "AFLIB/aflibConverter.h"
 #include "error_op.h"