diff --git a/include/boost/config/stdlib/dinkumware.hpp b/include/boost/config/stdlib/dinkumware.hpp
index 53d7d2a7..9e3fa18c 100644
--- a/include/boost/config/stdlib/dinkumware.hpp
+++ b/include/boost/config/stdlib/dinkumware.hpp
@@ -147,24 +147,13 @@
 #  define BOOST_NO_CXX11_STD_ALIGN
 #endif
 
-// I haven't been able to find any information
-// about what version of Dinkumware supports C++14.
-// The Dinkumware website says that they now support
-// C++14 but they give no further information about
-// their standard library. So I will use SD-6 or mark it
-// as unsupported until someone finds a version
-// of a compiler that uses the Dinkumware standard library
-// and they can see that shared_mutex is distributed in that
-// version and they can see the value of _CPPLIB_VER in rhat
-// version's yvals.h header file.
-//
 #if defined(__has_include)
 #if !__has_include(<shared_mutex>)
 #  define BOOST_NO_CXX14_HDR_SHARED_MUTEX
 #elif __cplusplus < 201402
 #  define BOOST_NO_CXX14_HDR_SHARED_MUTEX
 #endif
-#else
+#elif !defined(_CPPLIB_VER) || (_CPPLIB_VER < 650)
 #  define BOOST_NO_CXX14_HDR_SHARED_MUTEX
 #endif