1diff --git a/porttime/ptmacosx_mach.c b/porttime/ptmacosx_mach.c
2index 10c3554..712a974 100755
3--- a/porttime/ptmacosx_mach.c
4+++ b/porttime/ptmacosx_mach.c
5@@ -12,6 +12,7 @@
6
7 #include "porttime.h"
8 #include "sys/time.h"
9+#include "sys/qos.h"
10 #include "pthread.h"
11
12 #ifndef NSEC_PER_MSEC