diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b6bcce47940..7ad57299baa 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2008-08-28  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	* gtrh-posix.h: Fix uses of _POSIX_TIMEOUTS per the normal Posix
+	rule that a symbolic constant must be defined and >= 0 for the
+	corresponding facility to be present at compile-time.
+	* gthr-posix.c: Likewise.
+
 2008-08-28  Adam Nemet  <anemet@caviumnetworks.com>
 
 	* config/mips/mips.h (ISA_HAS_DMUL3): New macro.
diff --git a/gcc/gthr-posix.c b/gcc/gthr-posix.c
index bfcd316de30..154fc339416 100644
--- a/gcc/gthr-posix.c
+++ b/gcc/gthr-posix.c
@@ -112,12 +112,14 @@ pthread_mutex_trylock (pthread_mutex_t *mutex ATTRIBUTE_UNUSED)
 }
 
 #ifdef _POSIX_TIMEOUTS
+#if _POSIX_TIMEOUTS >= 0
 int
 pthread_mutex_timedlock (pthread_mutex_t *mutex ATTRIBUTE_UNUSED,
 			 const struct timespec *abs_timeout ATTRIBUTE_UNUSED)
 {
   return 0;
 }
+#endif
 #endif /* _POSIX_TIMEOUTS */
 
 int
diff --git a/gcc/gthr-posix.h b/gcc/gthr-posix.h
index e9612995cce..221833e0089 100644
--- a/gcc/gthr-posix.h
+++ b/gcc/gthr-posix.h
@@ -104,7 +104,9 @@ __gthrw3(sched_yield)
 __gthrw3(pthread_mutex_lock)
 __gthrw3(pthread_mutex_trylock)
 #ifdef _POSIX_TIMEOUTS
+#if _POSIX_TIMEOUTS >= 0
 __gthrw3(pthread_mutex_timedlock)
+#endif
 #endif /* _POSIX_TIMEOUTS */
 __gthrw3(pthread_mutex_unlock)
 __gthrw3(pthread_mutex_init)
@@ -131,7 +133,9 @@ __gthrw(sched_yield)
 __gthrw(pthread_mutex_lock)
 __gthrw(pthread_mutex_trylock)
 #ifdef _POSIX_TIMEOUTS
+#if _POSIX_TIMEOUTS >= 0
 __gthrw(pthread_mutex_timedlock)
+#endif
 #endif /* _POSIX_TIMEOUTS */
 __gthrw(pthread_mutex_unlock)
 __gthrw(pthread_mutex_init)
@@ -768,6 +772,7 @@ __gthread_mutex_trylock (__gthread_mutex_t *mutex)
 }
 
 #ifdef _POSIX_TIMEOUTS
+#if _POSIX_TIMEOUTS >= 0
 static inline int
 __gthread_mutex_timedlock (__gthread_mutex_t *mutex,
 			   const __gthread_time_t *abs_timeout)
@@ -778,6 +783,7 @@ __gthread_mutex_timedlock (__gthread_mutex_t *mutex,
     return 0;
 }
 #endif
+#endif
 
 static inline int
 __gthread_mutex_unlock (__gthread_mutex_t *mutex)
@@ -823,6 +829,7 @@ __gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex)
 }
 
 #ifdef _POSIX_TIMEOUTS
+#if _POSIX_TIMEOUTS >= 0
 static inline int
 __gthread_recursive_mutex_timedlock (__gthread_recursive_mutex_t *mutex,
 				     const __gthread_time_t *abs_timeout)
@@ -830,6 +837,7 @@ __gthread_recursive_mutex_timedlock (__gthread_recursive_mutex_t *mutex,
   return __gthread_mutex_timedlock (mutex, abs_timeout);
 }
 #endif
+#endif
 
 static inline int
 __gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex)