Index: sys/sys/time.h
===================================================================
--- sys/sys/time.h
+++ sys/sys/time.h
@@ -472,33 +472,40 @@
 };
 
 /* These macros are also in time.h. */
-#ifndef CLOCK_REALTIME
-#define	CLOCK_REALTIME	0
+#if __POSIX_VISIBLE >= 200109
+#define	CLOCK_REALTIME		0
 #endif
-#ifndef CLOCK_VIRTUAL
-#define	CLOCK_VIRTUAL	1
-#define	CLOCK_PROF	2
+#if __BSD_VISIBLE
+#define	CLOCK_VIRTUAL		1
+#define	CLOCK_PROF		2
+#endif
+#if __POSIX_VISIBLE >= 200109
+#define	CLOCK_MONOTONIC		4
 #endif
-#ifndef CLOCK_MONOTONIC
-#define	CLOCK_MONOTONIC	4
-#define	CLOCK_UPTIME	5		/* FreeBSD-specific. */
+#if __BSD_VISIBLE
+#define	CLOCK_UPTIME		5	/* FreeBSD-specific. */
 #define	CLOCK_UPTIME_PRECISE	7	/* FreeBSD-specific. */
 #define	CLOCK_UPTIME_FAST	8	/* FreeBSD-specific. */
 #define	CLOCK_REALTIME_PRECISE	9	/* FreeBSD-specific. */
 #define	CLOCK_REALTIME_FAST	10	/* FreeBSD-specific. */
 #define	CLOCK_MONOTONIC_PRECISE	11	/* FreeBSD-specific. */
 #define	CLOCK_MONOTONIC_FAST	12	/* FreeBSD-specific. */
-#define	CLOCK_SECOND	13		/* FreeBSD-specific. */
+#define	CLOCK_SECOND		13	/* FreeBSD-specific. */
+#endif
+#if __POSIX_VISIBLE >= 200109
 #define	CLOCK_THREAD_CPUTIME_ID	14
-#define	CLOCK_PROCESS_CPUTIME_ID	15
-
+#define	CLOCK_PROCESS_CPUTIME_ID 15
+#endif
+#if __BSD_VISIBLE
 #define	CLOCK_BOOTTIME		CLOCK_UPTIME		/* Linux compat */
 #define	CLOCK_REALTIME_COARSE	CLOCK_REALTIME_FAST	/* Linux compat */
 #define	CLOCK_MONOTONIC_COARSE	CLOCK_MONOTONIC_FAST	/* Linux compat */
 #endif
 
-#ifndef TIMER_ABSTIME
+#if __BSD_VISIBLE
 #define	TIMER_RELTIME	0x0	/* relative timer */
+#endif
+#if __POSIX_VISIBLE >= 200109
 #define	TIMER_ABSTIME	0x1	/* absolute timer */
 #endif