diff --git a/include/boost/smart_ptr/detail/sp_has_sync.hpp b/include/boost/smart_ptr/detail/sp_has_sync.hpp
index c266e75..3a1d346 100644
--- a/include/boost/smart_ptr/detail/sp_has_sync.hpp
+++ b/include/boost/smart_ptr/detail/sp_has_sync.hpp
@@ -20,7 +20,9 @@
 //  are available.
 //
 
-#if defined( __GNUC__ ) && ( __GNUC__ * 100 + __GNUC_MINOR__ >= 401 ) && !defined( BOOST_SP_NO_SYNC )
+#ifndef BOOST_SP_NO_SYNC
+
+#if defined( __GNUC__ ) && ( __GNUC__ * 100 + __GNUC_MINOR__ >= 401 )
 
 #define BOOST_SP_HAS_SYNC
 
@@ -52,6 +54,12 @@
 #undef BOOST_SP_HAS_SYNC
 #endif
 
-#endif // __GNUC__ * 100 + __GNUC_MINOR__ >= 401
+#elif defined( __IBMCPP__ ) && ( __IBMCPP__ >= 1210 )
+
+#define BOOST_SP_HAS_SYNC
+
+#endif
+
+#endif // #ifndef BOOST_SP_NO_SYNC
 
 #endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_HAS_SYNC_HPP_INCLUDED