diff --git a/include/boost/smart_ptr/detail/operator_bool.hpp b/include/boost/smart_ptr/detail/operator_bool.hpp
index 8ae1527..c0289b8 100644
--- a/include/boost/smart_ptr/detail/operator_bool.hpp
+++ b/include/boost/smart_ptr/detail/operator_bool.hpp
@@ -6,7 +6,8 @@
 //  See accompanying file LICENSE_1_0.txt or copy at
 //  http://www.boost.org/LICENSE_1_0.txt
 
-#if !defined( BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS ) && !defined( BOOST_NO_CXX11_NULLPTR )
+#if !defined( BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS ) && !defined( BOOST_NO_CXX11_NULLPTR )\
+    && !(defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x5130))
 
     explicit operator bool () const BOOST_NOEXCEPT
     {
diff --git a/include/boost/smart_ptr/detail/yield_k.hpp b/include/boost/smart_ptr/detail/yield_k.hpp
index 2dabc9f..44d1836 100644
--- a/include/boost/smart_ptr/detail/yield_k.hpp
+++ b/include/boost/smart_ptr/detail/yield_k.hpp
@@ -60,7 +60,16 @@ namespace detail
 {
 
 #if !defined( BOOST_USE_WINDOWS_H ) && !BOOST_PLAT_WINDOWS_RUNTIME
+#if !BOOST_COMP_CLANG || !defined __MINGW32__
   extern "C" void __stdcall Sleep( unsigned long ms );
+#else
+#include <_mingw.h>
+#if !defined __MINGW64_VERSION_MAJOR
+  extern "C" void __stdcall Sleep( unsigned long ms );
+#else
+  extern "C" __declspec(dllimport) void __stdcall Sleep( unsigned long ms );
+#endif
+#endif
 #endif
 
 inline void yield( unsigned k )