diff --git a/include/boost/atomic/detail/interlocked.hpp b/include/boost/atomic/detail/interlocked.hpp
index 62ebc26..1dd90d4 100644
--- a/include/boost/atomic/detail/interlocked.hpp
+++ b/include/boost/atomic/detail/interlocked.hpp
@@ -140,7 +140,11 @@ public:
 #define BOOST_ATOMIC_SHORT_LOCK_FREE 2
 #define BOOST_ATOMIC_INT_LOCK_FREE 2
 #define BOOST_ATOMIC_LONG_LOCK_FREE 2
+#if defined(_WIN64)
+#define BOOST_ATOMIC_LLONG_LOCK_FREE 2
+#else
 #define BOOST_ATOMIC_LLONG_LOCK_FREE 0
+#endif
 #define BOOST_ATOMIC_POINTER_LOCK_FREE 2
 #define BOOST_ATOMIC_BOOL_LOCK_FREE 2