diff --git a/hurd/hurdlock.c b/hurd/hurdlock.c
index 0787c19661..f8aa293e61 100644
--- a/hurd/hurdlock.c
+++ b/hurd/hurdlock.c
@@ -71,7 +71,7 @@ __lll_abstimed_lock (void *ptr,
     {
       if (atomic_exchange_acq ((int *)ptr, 2) == 0)
         return 0;
-      else if (tsp->tv_nsec < 0 || tsp->tv_nsec >= 1000000000)
+      else if (! valid_nanoseconds (tsp->tv_nsec))
         return EINVAL;
 
       int mlsec = compute_reltime (tsp, clk);
diff --git a/hurd/hurdselect.c b/hurd/hurdselect.c
index 333a909d67..79cd20b03e 100644
--- a/hurd/hurdselect.c
+++ b/hurd/hurdselect.c
@@ -27,6 +27,7 @@
 #include <assert.h>
 #include <stdint.h>
 #include <limits.h>
+#include <time.h>
 
 /* All user select types.  */
 #define SELECT_ALL (SELECT_READ | SELECT_WRITE | SELECT_URG)
@@ -89,8 +90,7 @@ _hurd_select (int nfds,
     {
       struct timeval now;
 
-      if (timeout->tv_sec < 0 || timeout->tv_nsec < 0 ||
-	  timeout->tv_nsec >= 1000000000)
+      if (timeout->tv_sec < 0 || ! valid_nanoseconds (timeout->tv_nsec))
 	{
 	  errno = EINVAL;
 	  return -1;
diff --git a/include/time.h b/include/time.h
index d93b16a781..68c6cc46cc 100644
--- a/include/time.h
+++ b/include/time.h
@@ -236,5 +236,13 @@ valid_timespec64_to_timeval (const struct __timespec64 ts64)
 
   return tv;
 }
+
+/* Check if a value is in the valid nanoseconds range. Return true if
+   it is, false otherwise.  */
+static inline bool
+valid_nanoseconds (long int ns)
+{
+  return __glibc_likely (0 <= ns && ns < 1000000000);
+}
 #endif
 #endif
diff --git a/io/ppoll.c b/io/ppoll.c
index a387924eeb..6d156a8a46 100644
--- a/io/ppoll.c
+++ b/io/ppoll.c
@@ -22,6 +22,7 @@
 #include <stddef.h>	/* For NULL.  */
 #include <sys/poll.h>
 #include <sysdep-cancel.h>
+#include <time.h>
 
 
 int
@@ -33,8 +34,7 @@ ppoll (struct pollfd *fds, nfds_t nfds, const struct timespec *timeout,
   /* poll uses a simple millisecond value.  Convert it.  */
   if (timeout != NULL)
     {
-      if (timeout->tv_sec < 0
-	  || timeout->tv_nsec < 0 || timeout->tv_nsec >= 1000000000)
+      if (timeout->tv_sec < 0 || ! valid_nanoseconds (timeout->tv_nsec))
 	{
 	  __set_errno (EINVAL);
 	  return -1;
diff --git a/nptl/lll_timedlock_wait.c b/nptl/lll_timedlock_wait.c
index 03060e874b..cd3cc3d371 100644
--- a/nptl/lll_timedlock_wait.c
+++ b/nptl/lll_timedlock_wait.c
@@ -21,6 +21,7 @@
 #include <errno.h>
 #include <lowlevellock.h>
 #include <sys/time.h>
+#include <time.h>
 
 
 int
@@ -28,7 +29,7 @@ __lll_clocklock_wait (int *futex, clockid_t clockid,
 		      const struct timespec *abstime, int private)
 {
   /* Reject invalid timeouts.  */
-  if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
+  if (! valid_nanoseconds (abstime->tv_nsec))
     return EINVAL;
 
   /* Try locking.  */
diff --git a/nptl/pthread_cond_wait.c b/nptl/pthread_cond_wait.c
index bacae09c02..cf372bc017 100644
--- a/nptl/pthread_cond_wait.c
+++ b/nptl/pthread_cond_wait.c
@@ -645,7 +645,7 @@ __pthread_cond_timedwait (pthread_cond_t *cond, pthread_mutex_t *mutex,
 {
   /* Check parameter validity.  This should also tell the compiler that
      it can assume that abstime is not NULL.  */
-  if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
+  if (! valid_nanoseconds (abstime->tv_nsec))
     return EINVAL;
 
   /* Relaxed MO is suffice because clock ID bit is only modified
@@ -668,7 +668,7 @@ __pthread_cond_clockwait (pthread_cond_t *cond, pthread_mutex_t *mutex,
 {
   /* Check parameter validity.  This should also tell the compiler that
      it can assume that abstime is not NULL.  */
-  if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
+  if (! valid_nanoseconds (abstime->tv_nsec))
     return EINVAL;
 
   if (!futex_abstimed_supported_clockid (clockid))
diff --git a/nptl/pthread_join_common.c b/nptl/pthread_join_common.c
index 9545ae4bd3..8b55c380e9 100644
--- a/nptl/pthread_join_common.c
+++ b/nptl/pthread_join_common.c
@@ -19,6 +19,7 @@
 #include "pthreadP.h"
 #include <atomic.h>
 #include <stap-probe.h>
+#include <time.h>
 
 static void
 cleanup (void *arg)
@@ -40,7 +41,7 @@ timedwait_tid (pid_t *tidp, const struct timespec *abstime)
 {
   pid_t tid;
 
-  if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
+  if (! valid_nanoseconds (abstime->tv_nsec))
     return EINVAL;
 
   /* Repeat until thread terminated.  */
diff --git a/nptl/pthread_mutex_timedlock.c b/nptl/pthread_mutex_timedlock.c
index a0ce044dd4..c9bb3b9176 100644
--- a/nptl/pthread_mutex_timedlock.c
+++ b/nptl/pthread_mutex_timedlock.c
@@ -235,7 +235,7 @@ __pthread_mutex_clocklock_common (pthread_mutex_t *mutex,
 	    }
 
 	  /* We are about to block; check whether the timeout is invalid.  */
-	  if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
+	  if (! valid_nanoseconds (abstime->tv_nsec))
 	    return EINVAL;
 	  /* Work around the fact that the kernel rejects negative timeout
 	     values despite them being valid.  */
@@ -561,7 +561,7 @@ __pthread_mutex_clocklock_common (pthread_mutex_t *mutex,
 		if (oldval != ceilval)
 		  {
 		    /* Reject invalid timeouts.  */
-		    if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
+		    if (! valid_nanoseconds (abstime->tv_nsec))
 		      {
 			result = EINVAL;
 			goto failpp;
diff --git a/nptl/pthread_rwlock_common.c b/nptl/pthread_rwlock_common.c
index 7070b9c2c8..9c05e03a09 100644
--- a/nptl/pthread_rwlock_common.c
+++ b/nptl/pthread_rwlock_common.c
@@ -24,6 +24,7 @@
 #include <stap-probe.h>
 #include <atomic.h>
 #include <futex-internal.h>
+#include <time.h>
 
 
 /* A reader--writer lock that fulfills the POSIX requirements (but operations
@@ -290,8 +291,7 @@ __pthread_rwlock_rdlock_full (pthread_rwlock_t *rwlock,
      if the lock can be immediately acquired" (i.e., we need not but may check
      it).  */
   if (abstime && __glibc_unlikely (!futex_abstimed_supported_clockid (clockid)
-      || abstime->tv_nsec >= 1000000000
-      || abstime->tv_nsec < 0))
+      || ! valid_nanoseconds (abstime->tv_nsec)))
     return EINVAL;
 
   /* Make sure we are not holding the rwlock as a writer.  This is a deadlock
@@ -596,8 +596,7 @@ __pthread_rwlock_wrlock_full (pthread_rwlock_t *rwlock,
      if the lock can be immediately acquired" (i.e., we need not but may check
      it).  */
   if (abstime && __glibc_unlikely (!futex_abstimed_supported_clockid (clockid)
-      || abstime->tv_nsec >= 1000000000
-      || abstime->tv_nsec < 0))
+      || ! valid_nanoseconds (abstime->tv_nsec)))
     return EINVAL;
 
   /* Make sure we are not holding the rwlock as a writer.  This is a deadlock
diff --git a/nptl/sem_clockwait.c b/nptl/sem_clockwait.c
index 9ed98c4cce..21628df524 100644
--- a/nptl/sem_clockwait.c
+++ b/nptl/sem_clockwait.c
@@ -18,6 +18,7 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#include <time.h>
 #include "sem_waitcommon.c"
 
 int
@@ -32,7 +33,7 @@ sem_clockwait (sem_t *sem, clockid_t clockid,
       return -1;
     }
 
-  if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
+  if (! valid_nanoseconds (abstime->tv_nsec))
     {
       __set_errno (EINVAL);
       return -1;
diff --git a/nptl/sem_timedwait.c b/nptl/sem_timedwait.c
index fbb50a5fc8..a3fbe8998b 100644
--- a/nptl/sem_timedwait.c
+++ b/nptl/sem_timedwait.c
@@ -17,6 +17,7 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#include <time.h>
 #include "sem_waitcommon.c"
 
 /* This is in a separate file because because sem_timedwait is only provided
@@ -24,7 +25,7 @@
 int
 sem_timedwait (sem_t *sem, const struct timespec *abstime)
 {
-  if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
+  if (! valid_nanoseconds (abstime->tv_nsec))
     {
       __set_errno (EINVAL);
       return -1;
diff --git a/sysdeps/htl/pt-cond-timedwait.c b/sysdeps/htl/pt-cond-timedwait.c
index cc5a9db37f..ff5631f7ab 100644
--- a/sysdeps/htl/pt-cond-timedwait.c
+++ b/sysdeps/htl/pt-cond-timedwait.c
@@ -20,6 +20,7 @@
 
 #include <pt-internal.h>
 #include <pthreadP.h>
+#include <time.h>
 
 extern int __pthread_cond_timedwait_internal (pthread_cond_t *cond,
 					      pthread_mutex_t *mutex,
@@ -74,7 +75,7 @@ __pthread_cond_timedwait_internal (pthread_cond_t *cond,
   int cancelled, oldtype, drain;
   clockid_t clock_id = __pthread_default_condattr.__clock;
 
-  if (abstime && (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000))
+  if (abstime && ! valid_nanoseconds (abstime->tv_nsec))
     return EINVAL;
 
   struct __pthread *self = _pthread_self ();
diff --git a/sysdeps/htl/pt-mutex-timedlock.c b/sysdeps/htl/pt-mutex-timedlock.c
index c8fe022613..c378557f49 100644
--- a/sysdeps/htl/pt-mutex-timedlock.c
+++ b/sysdeps/htl/pt-mutex-timedlock.c
@@ -18,6 +18,7 @@
 
 #include <pthread.h>
 #include <assert.h>
+#include <time.h>
 
 #include <pt-internal.h>
 
@@ -119,7 +120,7 @@ __pthread_mutex_timedlock_internal (struct __pthread_mutex *mutex,
 #endif
     assert (mutex->__owner);
 
-  if (abstime != NULL && (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000))
+  if (abstime != NULL && ! valid_nanoseconds (abstime->tv_nsec))
     return EINVAL;
 
   /* Add ourselves to the queue.  */
diff --git a/sysdeps/htl/pt-rwlock-timedrdlock.c b/sysdeps/htl/pt-rwlock-timedrdlock.c
index cdae8dfd3a..d64c7a7390 100644
--- a/sysdeps/htl/pt-rwlock-timedrdlock.c
+++ b/sysdeps/htl/pt-rwlock-timedrdlock.c
@@ -18,6 +18,7 @@
 
 #include <pthread.h>
 #include <assert.h>
+#include <time.h>
 
 #include <pt-internal.h>
 
@@ -60,7 +61,7 @@ __pthread_rwlock_timedrdlock_internal (struct __pthread_rwlock *rwlock,
   /* Better be blocked by a writer.  */
   assert (rwlock->__readers == 0);
 
-  if (abstime != NULL && (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000))
+  if (abstime != NULL && ! valid_nanoseconds (abstime->tv_nsec))
     return EINVAL;
 
   self = _pthread_self ();
diff --git a/sysdeps/htl/pt-rwlock-timedwrlock.c b/sysdeps/htl/pt-rwlock-timedwrlock.c
index 83a022afed..2316321d79 100644
--- a/sysdeps/htl/pt-rwlock-timedwrlock.c
+++ b/sysdeps/htl/pt-rwlock-timedwrlock.c
@@ -18,6 +18,7 @@
 
 #include <pthread.h>
 #include <assert.h>
+#include <time.h>
 
 #include <pt-internal.h>
 
@@ -46,7 +47,7 @@ __pthread_rwlock_timedwrlock_internal (struct __pthread_rwlock *rwlock,
 
   /* The lock is busy.  */
 
-  if (abstime != NULL && (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000))
+  if (abstime != NULL && ! valid_nanoseconds (abstime->tv_nsec))
     return EINVAL;
 
   self = _pthread_self ();
diff --git a/sysdeps/htl/sem-timedwait.c b/sysdeps/htl/sem-timedwait.c
index e2eeff4b8a..dfb0cb99d3 100644
--- a/sysdeps/htl/sem-timedwait.c
+++ b/sysdeps/htl/sem-timedwait.c
@@ -19,6 +19,7 @@
 #include <semaphore.h>
 #include <errno.h>
 #include <assert.h>
+#include <time.h>
 
 #include <pt-internal.h>
 
@@ -39,7 +40,7 @@ __sem_timedwait_internal (sem_t *restrict sem,
       return 0;
     }
 
-  if (timeout != NULL && (timeout->tv_nsec < 0 || timeout->tv_nsec >= 1000000000))
+  if (timeout != NULL && ! valid_nanoseconds (timeout->tv_nsec))
     {
       errno = EINVAL;
       return -1;
diff --git a/sysdeps/mach/hurd/htl/pt-hurd-cond-timedwait.c b/sysdeps/mach/hurd/htl/pt-hurd-cond-timedwait.c
index cf0de47bb5..aa3eb9884c 100644
--- a/sysdeps/mach/hurd/htl/pt-hurd-cond-timedwait.c
+++ b/sysdeps/mach/hurd/htl/pt-hurd-cond-timedwait.c
@@ -19,6 +19,7 @@
 #include <pthread.h>
 #include <assert.h>
 #include <hurd/signal.h>
+#include <time.h>
 
 #include <pt-internal.h>
 
@@ -69,7 +70,7 @@ __pthread_hurd_cond_timedwait_internal (pthread_cond_t *cond,
 
   assert (ss->intr_port == MACH_PORT_NULL);	/* Sanity check for signal bugs. */
 
-  if (abstime != NULL && (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000))
+  if (abstime != NULL && ! valid_nanoseconds (abstime->tv_nsec))
     return EINVAL;
 
   /* Atomically enqueue our thread on the condition variable's queue of
diff --git a/sysdeps/mach/nanosleep.c b/sysdeps/mach/nanosleep.c
index 67caa3ea8a..555251f842 100644
--- a/sysdeps/mach/nanosleep.c
+++ b/sysdeps/mach/nanosleep.c
@@ -30,8 +30,7 @@ __libc_nanosleep (const struct timespec *requested_time,
   struct timeval before, after;
 
   if (requested_time->tv_sec < 0
-      || requested_time->tv_nsec < 0
-      || requested_time->tv_nsec >= 1000000000)
+      || ! valid_nanoseconds (requested_time->tv_nsec))
     {
       errno = EINVAL;
       return -1;
diff --git a/sysdeps/pthread/timer_settime.c b/sysdeps/pthread/timer_settime.c
index 3d20495283..0fad4b1983 100644
--- a/sysdeps/pthread/timer_settime.c
+++ b/sysdeps/pthread/timer_settime.c
@@ -41,10 +41,8 @@ timer_settime (timer_t timerid, int flags, const struct itimerspec *value,
       goto bail;
     }
 
-  if (value->it_interval.tv_nsec < 0
-      || value->it_interval.tv_nsec >= 1000000000
-      || value->it_value.tv_nsec < 0
-      || value->it_value.tv_nsec >= 1000000000)
+  if (! valid_nanoseconds (value->it_interval.tv_nsec)
+      || ! valid_nanoseconds (value->it_value.tv_nsec))
     {
       __set_errno (EINVAL);
       goto bail;
diff --git a/sysdeps/sparc/sparc32/lowlevellock.c b/sysdeps/sparc/sparc32/lowlevellock.c
index 25f3e6b1a0..074ecf0636 100644
--- a/sysdeps/sparc/sparc32/lowlevellock.c
+++ b/sysdeps/sparc/sparc32/lowlevellock.c
@@ -21,6 +21,7 @@
 #include <sysdep.h>
 #include <lowlevellock.h>
 #include <sys/time.h>
+#include <time.h>
 
 
 void
@@ -56,7 +57,7 @@ __lll_clocklock_wait (int *futex, clockid_t clockid,
                       const struct timespec *abstime, int private)
 {
   /* Reject invalid timeouts.  */
-  if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
+  if (! valid_nanoseconds (abstime->tv_nsec))
     return EINVAL;
 
   do
diff --git a/sysdeps/unix/clock_nanosleep.c b/sysdeps/unix/clock_nanosleep.c
index 95b4956b12..8514a439ee 100644
--- a/sysdeps/unix/clock_nanosleep.c
+++ b/sysdeps/unix/clock_nanosleep.c
@@ -30,8 +30,7 @@ __clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
 {
   struct timespec now;
 
-  if (__builtin_expect (req->tv_nsec, 0) < 0
-      || __builtin_expect (req->tv_nsec, 0) >= 1000000000)
+  if (! valid_nanoseconds (req->tv_nsec))
     return EINVAL;
 
   if (clock_id == CLOCK_THREAD_CPUTIME_ID)
diff --git a/sysdeps/unix/clock_settime.c b/sysdeps/unix/clock_settime.c
index 18d7c99864..54c917949f 100644
--- a/sysdeps/unix/clock_settime.c
+++ b/sysdeps/unix/clock_settime.c
@@ -27,7 +27,7 @@ __clock_settime (clockid_t clock_id, const struct timespec *tp)
   int retval = -1;
 
   /* Make sure the time cvalue is OK.  */
-  if (tp->tv_nsec < 0 || tp->tv_nsec >= 1000000000)
+  if (! valid_nanoseconds (tp->tv_nsec))
     {
       __set_errno (EINVAL);
       return -1;
diff --git a/sysdeps/unix/sysv/linux/clock_settime.c b/sysdeps/unix/sysv/linux/clock_settime.c
index 54999d3008..bda113809b 100644
--- a/sysdeps/unix/sysv/linux/clock_settime.c
+++ b/sysdeps/unix/sysv/linux/clock_settime.c
@@ -26,7 +26,7 @@ int
 __clock_settime64 (clockid_t clock_id, const struct __timespec64 *tp)
 {
   /* Make sure the time cvalue is OK.  */
-  if (tp->tv_nsec < 0 || tp->tv_nsec >= 1000000000)
+  if (! valid_nanoseconds (tp->tv_nsec))
     {
       __set_errno (EINVAL);
       return -1;
diff --git a/time/clock_nanosleep.c b/time/clock_nanosleep.c
index f3230c4c90..5952d29195 100644
--- a/time/clock_nanosleep.c
+++ b/time/clock_nanosleep.c
@@ -24,8 +24,7 @@ int
 __clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
 		   struct timespec *rem)
 {
-  if (__builtin_expect (req->tv_nsec, 0) < 0
-      || __builtin_expect (req->tv_nsec, 0) >= 1000000000)
+  if (! valid_nanoseconds (req->tv_nsec))
     return EINVAL;
 
   if (flags != TIMER_ABSTIME && flags != 0)
