1--- srt/common/srt_compat.h_old	2018-12-20 02:07:53.000000000 +0100
2+++ srt/common/srt_compat.h	2018-12-20 02:09:23.000000000 +0100
3@@ -82,7 +82,7 @@
4 {
5 #if defined(__SRT_OSX_CLOCK_GETTIME_AVAILABILITY) \
6    && (__SRT_OSX_CLOCK_GETTIME_AVAILABILITY == 1)
7-   if (&clock_gettime != NULL)
8+   if (__builtin_available(macOS 10.12, iOS 10.0, tvOS 10.0, *))
9    {
10       return clock_gettime(clock_id, ts);
11    }
12@@ -95,7 +95,7 @@
13 {
14 #if defined(__SRT_OSX_CLOCK_GETTIME_AVAILABILITY) \
15    && (__SRT_OSX_CLOCK_GETTIME_AVAILABILITY == 1)
16-   if (&clock_getres != NULL)
17+   if (__builtin_available(macOS 10.12, iOS 10.0, tvOS 10.0, *))
18    {
19       return clock_getres(clock_id, ts);
20    }
21