diff --git a/include/boost/thread/pthread/mutex.hpp b/include/boost/thread/pthread/mutex.hpp
index f33f5b12..1292c837 100644
--- a/include/boost/thread/pthread/mutex.hpp
+++ b/include/boost/thread/pthread/mutex.hpp
@@ -26,10 +26,12 @@
 #include <boost/thread/detail/delete.hpp>
 
 #ifdef _POSIX_TIMEOUTS
-#if _POSIX_TIMEOUTS >= 0 && _POSIX_C_SOURCE>=200112L
+#if _POSIX_TIMEOUTS >= 0 && _POSIX_TIMEOUTS>=200112L
+#ifndef BOOST_PTHREAD_HAS_TIMEDLOCK
 #define BOOST_PTHREAD_HAS_TIMEDLOCK
 #endif
 #endif
+#endif
 
 #include <boost/config/abi_prefix.hpp>
 
diff --git a/include/boost/thread/pthread/recursive_mutex.hpp b/include/boost/thread/pthread/recursive_mutex.hpp
index 5cfcf9f7..9330d77d 100644
--- a/include/boost/thread/pthread/recursive_mutex.hpp
+++ b/include/boost/thread/pthread/recursive_mutex.hpp
@@ -28,10 +28,13 @@
 #include <boost/thread/detail/delete.hpp>
 
 #ifdef _POSIX_TIMEOUTS
-#if _POSIX_TIMEOUTS >= 0
+#if _POSIX_TIMEOUTS >= 0 && _POSIX_TIMEOUTS>=200112L
+#ifndef BOOST_PTHREAD_HAS_TIMEDLOCK
 #define BOOST_PTHREAD_HAS_TIMEDLOCK
 #endif
 #endif
+#endif
+
 
 #if defined(BOOST_HAS_PTHREAD_MUTEXATTR_SETTYPE) && defined(BOOST_PTHREAD_HAS_TIMEDLOCK)
 #define BOOST_USE_PTHREAD_RECURSIVE_TIMEDLOCK