diff --git a/CMakeLists.txt b/CMakeLists.txt
index b4ad27b..6622ac0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -38,8 +38,6 @@ target_link_libraries(boost_coroutine
     Boost::throw_exception
     Boost::type_traits
     Boost::utility
-  PRIVATE
-    Boost::thread
 )
 
 target_compile_definitions(boost_coroutine
diff --git a/build/Jamfile.v2 b/build/Jamfile.v2
index 584edf5..f1a0a4d 100644
--- a/build/Jamfile.v2
+++ b/build/Jamfile.v2
@@ -11,7 +11,6 @@ import toolset ;
 project boost/coroutine
     : requirements
       <library>/boost/context//boost_context
-      <library>/boost/thread//boost_thread
       <target-os>linux,<toolset>gcc,<segmented-stacks>on:<cxxflags>-fsplit-stack
       <target-os>linux,<toolset>gcc,<segmented-stacks>on:<cxxflags>-DBOOST_USE_SEGMENTED_STACKS
       <toolset>clang,<segmented-stacks>on:<cxxflags>-fsplit-stack
@@ -39,7 +38,6 @@ lib boost_coroutine
       exceptions.cpp
       stack_traits_sources
     : <link>shared:<library>../../context/build//boost_context
-      <link>shared:<library>../../thread/build//boost_thread
     ;
 
 boost-install boost_coroutine ;
diff --git a/src/posix/stack_traits.cpp b/src/posix/stack_traits.cpp
index b629943..7a467b7 100644
--- a/src/posix/stack_traits.cpp
+++ b/src/posix/stack_traits.cpp
@@ -19,7 +19,7 @@ extern "C" {
 #include <cmath>
 
 #include <boost/assert.hpp>
-#include <boost/thread.hpp>
+#include <boost/config.hpp>
 
 #if !defined (SIGSTKSZ)
 # define SIGSTKSZ (8 * 1024)
@@ -32,36 +32,27 @@ extern "C" {
 
 namespace {
 
-void pagesize_( std::size_t * size)
-{
-    // conform to POSIX.1-2001
-    * size = ::sysconf( _SC_PAGESIZE);
-}
-
-void stacksize_limit_( rlimit * limit)
-{
-    // conforming to POSIX.1-2001
-#if defined(BOOST_DISABLE_ASSERTS) || defined(NDEBUG)
-    ::getrlimit( RLIMIT_STACK, limit);
-#else
-    const int result = ::getrlimit( RLIMIT_STACK, limit);
-    BOOST_ASSERT( 0 == result);
-#endif
-}
-
 std::size_t pagesize()
 {
-    static std::size_t size = 0;
-    static boost::once_flag flag;
-    boost::call_once( flag, pagesize_, & size);
-    return size;
+    // conform to POSIX.1-2001
+    return ::sysconf( _SC_PAGESIZE);
 }
 
-rlimit stacksize_limit()
+rlim_t stacksize_limit_()
 {
-    static rlimit limit;
-    static boost::once_flag flag;
-    boost::call_once( flag, stacksize_limit_, & limit);
+    rlimit limit;
+    // conforming to POSIX.1-2001
+#if defined(BOOST_DISABLE_ASSERTS) || defined(NDEBUG)
+    ::getrlimit( RLIMIT_STACK, & limit);
+#else
+    const int result = ::getrlimit( RLIMIT_STACK, & limit);
+    BOOST_ASSERT( 0 == result);
+#endif
+    return limit.rlim_max;
+}
+
+rlim_t stacksize_limit() BOOST_NOEXCEPT_OR_NOTHROW {
+    static rlim_t limit = stacksize_limit_();
     return limit;
 }
 
@@ -72,11 +63,14 @@ namespace coroutines {
 
 bool
 stack_traits::is_unbounded() BOOST_NOEXCEPT
-{ return RLIM_INFINITY == stacksize_limit().rlim_max; }
+{ return RLIM_INFINITY == stacksize_limit(); }
 
 std::size_t
 stack_traits::page_size() BOOST_NOEXCEPT
-{ return pagesize(); }
+{
+    static std::size_t size = pagesize();
+    return size;
+}
 
 std::size_t
 stack_traits::default_size() BOOST_NOEXCEPT
@@ -98,7 +92,7 @@ std::size_t
 stack_traits::maximum_size() BOOST_NOEXCEPT
 {
     BOOST_ASSERT( ! is_unbounded() );
-    return static_cast< std::size_t >( stacksize_limit().rlim_max);
+    return static_cast< std::size_t >( stacksize_limit() );
 }
 
 }}
diff --git a/src/windows/stack_traits.cpp b/src/windows/stack_traits.cpp
index bdf417a..a31ebb5 100644
--- a/src/windows/stack_traits.cpp
+++ b/src/windows/stack_traits.cpp
@@ -20,7 +20,6 @@ extern "C" {
 
 #include <boost/assert.hpp>
 #include <boost/coroutine/detail/config.hpp>
-#include <boost/thread.hpp>
 
 #include <boost/coroutine/stack_context.hpp>
 
@@ -44,25 +43,11 @@ extern "C" {
 
 namespace {
 
-void system_info_( SYSTEM_INFO * si)
-{ ::GetSystemInfo( si); }
-
-SYSTEM_INFO system_info()
-{
-    static SYSTEM_INFO si;
-    static boost::once_flag flag;
-    boost::call_once( flag, static_cast< void(*)( SYSTEM_INFO *) >( system_info_), & si);
-    return si;
-}
-
 std::size_t pagesize()
-{ return static_cast< std::size_t >( system_info().dwPageSize); }
-
-std::size_t page_count( std::size_t stacksize)
 {
-    return static_cast< std::size_t >(
-        std::floor(
-            static_cast< float >( stacksize) / pagesize() ) );
+    SYSTEM_INFO si;
+    ::GetSystemInfo(&si);
+    return static_cast< std::size_t >( si.dwPageSize );
 }
 
 }
@@ -78,7 +63,10 @@ stack_traits::is_unbounded() BOOST_NOEXCEPT
 
 std::size_t
 stack_traits::page_size() BOOST_NOEXCEPT
-{ return pagesize(); }
+{
+    static std::size_t size = pagesize();
+    return size;
+}
 
 std::size_t
 stack_traits::default_size() BOOST_NOEXCEPT