Index: libs/thread/test/threads/this_thread/sleep_until/sleep_until_pass.cpp
===================================================================
--- libs/thread/test/threads/this_thread/sleep_until/sleep_until_pass.cpp	(revision 78797)
+++ libs/thread/test/threads/this_thread/sleep_until/sleep_until_pass.cpp	(working copy)
@@ -16,7 +16,7 @@
 // thread::id this_thread::get_id();
 
 #include <boost/thread/thread.hpp>
-#include <cstdlib>
+#include <algorithm>
 
 #include <boost/detail/lightweight_test.hpp>
 
@@ -35,7 +35,7 @@
   boost::chrono::nanoseconds err = ms / 100;
   // The time slept is within 1% of 500ms
   // This test is spurious as it depends on the time the thread system switches the threads
-  BOOST_TEST(std::abs(static_cast<long>(ns.count())) < (err+boost::chrono::milliseconds(1000)).count());
+  BOOST_TEST(std::max(ns, -ns) < (err+boost::chrono::milliseconds(1000)));
 
 }
 
Index: libs/thread/test/threads/this_thread/sleep_for/sleep_for_pass.cpp
===================================================================
--- libs/thread/test/threads/this_thread/sleep_for/sleep_for_pass.cpp	(revision 78797)
+++ libs/thread/test/threads/this_thread/sleep_for/sleep_for_pass.cpp	(working copy)
@@ -16,7 +16,7 @@
 // thread::id this_thread::get_id();
 
 #include <boost/thread/thread.hpp>
-#include <cstdlib>
+#include <algorithm>
 
 #include <boost/detail/lightweight_test.hpp>
 
@@ -35,7 +35,7 @@
   boost::chrono::nanoseconds err = ms / 100;
   // The time slept is within 1% of 500ms
   // This test is spurious as it depends on the time the thread system switches the threads
-  BOOST_TEST(std::abs(static_cast<long>(ns.count())) < (err+boost::chrono::milliseconds(1000)).count());
+  BOOST_TEST(std::max(ns, -ns) < (err/*+boost::chrono::milliseconds(1000)*/));
   return boost::report_errors();
 
 }