diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index e4ca68dee85..c0307d23989 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -16,6 +16,14 @@
 	(unlock_shared): Add Debug Mode assertion.
 	* testsuite/30_threads/shared_timed_mutex/try_lock/3.cc: New.
 
+	* include/std/shared_mutex (shared_timed_mutex): Only use
+	pthread_rwlock_t when the POSIX Timeouts option is supported.
+	* testsuite/30_threads/shared_lock/cons/5.cc: Remove
+	dg-require-gthreads-timed.
+	* testsuite/30_threads/shared_lock/cons/6.cc: Likewise.
+	* testsuite/30_threads/shared_lock/locking/3.cc: Likewise.
+	* testsuite/30_threads/shared_lock/locking/4.cc: Likewise.
+
 2015-04-09  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* config/abi/post/x86_64-linux-gnu/x32/baseline_symbols.txt: Update.
diff --git a/libstdc++-v3/include/std/shared_mutex b/libstdc++-v3/include/std/shared_mutex
index 7f26465788b..b72a822a57b 100644
--- a/libstdc++-v3/include/std/shared_mutex
+++ b/libstdc++-v3/include/std/shared_mutex
@@ -57,7 +57,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   /// shared_timed_mutex
   class shared_timed_mutex
   {
-#ifdef _GLIBCXX_USE_PTHREAD_RWLOCK_T
+#if _GLIBCXX_USE_PTHREAD_RWLOCK_T && _GTHREAD_USE_MUTEX_TIMEDLOCK
     typedef chrono::system_clock	__clock_t;
 
 #ifdef PTHREAD_RWLOCK_INITIALIZER
@@ -116,7 +116,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       return true;
     }
 
-#if _GTHREAD_USE_MUTEX_TIMEDLOCK
     template<typename _Rep, typename _Period>
       bool
       try_lock_for(const chrono::duration<_Rep, _Period>& __rel_time)
@@ -158,7 +157,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	const auto __s_atime = __s_entry + __delta;
 	return try_lock_until(__s_atime);
       }
-#endif
 
     void
     unlock()
@@ -200,7 +198,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       return true;
     }
 
-#if _GTHREAD_USE_MUTEX_TIMEDLOCK
     template<typename _Rep, typename _Period>
       bool
       try_lock_shared_for(const chrono::duration<_Rep, _Period>& __rel_time)
@@ -258,7 +255,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	const auto __s_atime = __s_entry + __delta;
 	return try_lock_shared_until(__s_atime);
       }
-#endif
 
     void
     unlock_shared()
@@ -266,7 +262,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       unlock();
     }
 
-#else // ! _GLIBCXX_USE_PTHREAD_RWLOCK_T
+#else // ! (_GLIBCXX_USE_PTHREAD_RWLOCK_T && _GTHREAD_USE_MUTEX_TIMEDLOCK)
 
     // Must use the same clock as condition_variable
     typedef chrono::system_clock	__clock_t;
@@ -459,7 +455,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	    _M_gate1.notify_one();
 	}
     }
-#endif // ! _GLIBCXX_USE_PTHREAD_RWLOCK_T
+#endif // _GLIBCXX_USE_PTHREAD_RWLOCK_T && _GTHREAD_USE_MUTEX_TIMEDLOCK
   };
 #endif // _GLIBCXX_HAS_GTHREADS
 
diff --git a/libstdc++-v3/testsuite/30_threads/shared_lock/cons/5.cc b/libstdc++-v3/testsuite/30_threads/shared_lock/cons/5.cc
index 63ab5149a73..9ec0498620a 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_lock/cons/5.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_lock/cons/5.cc
@@ -3,7 +3,6 @@
 // { dg-options " -std=gnu++14 -pthreads" { target *-*-solaris* } }
 // { dg-options " -std=gnu++14 " { target *-*-cygwin *-*-darwin* } }
 // { dg-require-cstdint "" }
-// { dg-require-gthreads-timed "" }
 
 // Copyright (C) 2013-2015 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/shared_lock/cons/6.cc b/libstdc++-v3/testsuite/30_threads/shared_lock/cons/6.cc
index 8b2bcd5e492..2074bbefd48 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_lock/cons/6.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_lock/cons/6.cc
@@ -3,7 +3,6 @@
 // { dg-options " -std=gnu++14 -pthreads" { target *-*-solaris* } }
 // { dg-options " -std=gnu++14 " { target *-*-cygwin *-*-darwin* } }
 // { dg-require-cstdint "" }
-// { dg-require-gthreads-timed "" }
 
 // Copyright (C) 2013-2015 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/shared_lock/locking/3.cc b/libstdc++-v3/testsuite/30_threads/shared_lock/locking/3.cc
index b67022a0f42..4b653eafe43 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_lock/locking/3.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_lock/locking/3.cc
@@ -3,7 +3,6 @@
 // { dg-options " -std=gnu++14 -pthreads" { target *-*-solaris* } }
 // { dg-options " -std=gnu++14 " { target *-*-cygwin *-*-darwin* } }
 // { dg-require-cstdint "" }
-// { dg-require-gthreads-timed "" }
 
 // Copyright (C) 2013-2015 Free Software Foundation, Inc.
 //
diff --git a/libstdc++-v3/testsuite/30_threads/shared_lock/locking/4.cc b/libstdc++-v3/testsuite/30_threads/shared_lock/locking/4.cc
index e87d0dd73a1..afeefa2aca0 100644
--- a/libstdc++-v3/testsuite/30_threads/shared_lock/locking/4.cc
+++ b/libstdc++-v3/testsuite/30_threads/shared_lock/locking/4.cc
@@ -3,7 +3,6 @@
 // { dg-options " -std=gnu++14 -pthreads" { target *-*-solaris* } }
 // { dg-options " -std=gnu++14 " { target *-*-cygwin *-*-darwin* } }
 // { dg-require-cstdint "" }
-// { dg-require-gthreads-timed "" }
 
 // Copyright (C) 2013-2015 Free Software Foundation, Inc.
 //