diff --git a/src/platforms/posix/px4_layer/px4_posix_impl.cpp b/src/platforms/posix/px4_layer/px4_posix_impl.cpp
index 94387f648b..37132a0641 100644
--- a/src/platforms/posix/px4_layer/px4_posix_impl.cpp
+++ b/src/platforms/posix/px4_layer/px4_posix_impl.cpp
@@ -48,6 +48,7 @@
 #include "systemlib/param/param.h"
 #include "hrt_work.h"
 #include <drivers/drv_hrt.h>
+#include "px4_time.h"
 
 extern pthread_t _shell_task_id;
 
@@ -55,8 +56,26 @@ __BEGIN_DECLS
 
 long PX4_TICKS_PER_SEC = sysconf(_SC_CLK_TCK);
 
+#ifdef __PX4_DARWIN
 extern void hrt_init(void);
 
+int px4_clock_gettime(clockid_t clk_id, struct timespec *tp)
+{
+	uint64_t currtime = hrt_absolute_time();
+
+	tp->tv_sec = currtime / (1000 * 1000);
+	tp->tv_nsec = (currtime - (currtime * 1000 * 1000)) * 1000;
+
+	return 0;
+}
+
+int px4_clock_settime(clockid_t clk_id, struct timespec *tp)
+{
+	/* do nothing right now */
+}
+
+#endif
+
 __END_DECLS
 
 namespace px4
diff --git a/src/platforms/px4_tasks.h b/src/platforms/px4_tasks.h
index 3d36a65cfd..9dc237e63b 100644
--- a/src/platforms/px4_tasks.h
+++ b/src/platforms/px4_tasks.h
@@ -80,6 +80,12 @@ typedef int px4_task_t;
 #error "No target OS defined"
 #endif
 
+#if defined (__PX4_LINUX) || defined(__PX4_NUTTX)
+#include <sys/prctl.h>
+#else
+#define prctl(_action, _string, _pid)
+#endif
+
 typedef int px4_task_t;
 
 typedef struct {
diff --git a/src/platforms/px4_time.h b/src/platforms/px4_time.h
index 5a93dedf40..22751b3a99 100644
--- a/src/platforms/px4_time.h
+++ b/src/platforms/px4_time.h
@@ -8,6 +8,20 @@
 #define px4_clock_gettime clock_gettime
 #define px4_clock_settime clock_settime
 
+#elif defined(__PX4_DARWIN)
+
+__BEGIN_DECLS
+
+#define clockid_t unsigned
+#define CLOCK_REALTIME 0
+
+int px4_clock_gettime(clockid_t clk_id, struct timespec *tp);
+int px4_clock_settime(clockid_t clk_id, struct timespec *tp);
+
+__EXPORT unsigned int sleep(unsigned int sec);
+
+__END_DECLS
+
 #elif defined(__PX4_QURT)
 
 #include <sys/timespec.h>