diff --git a/include/boost/config/stdlib/dinkumware.hpp b/include/boost/config/stdlib/dinkumware.hpp
index 0895e150..dc16614b 100644
--- a/include/boost/config/stdlib/dinkumware.hpp
+++ b/include/boost/config/stdlib/dinkumware.hpp
@@ -59,7 +59,7 @@
 #  define BOOST_NO_STD_ITERATOR_TRAITS
 #endif
 
-#if defined(_ICL) && defined(_CPPLIB_VER) && (_CPPLIB_VER <= 310)
+#if defined(__ICL) && defined(_CPPLIB_VER) && (_CPPLIB_VER <= 310)
 // Intel C++ chokes over any non-trivial use of <locale>
 // this may be an overly restrictive define, but regex fails without it:
 #  define BOOST_NO_STD_LOCALE
@@ -75,3 +75,4 @@
 
 
 
+