diff --git a/include/boost/config/compiler/digitalmars.hpp b/include/boost/config/compiler/digitalmars.hpp
index 32fc71fa..f5734c0c 100644
--- a/include/boost/config/compiler/digitalmars.hpp
+++ b/include/boost/config/compiler/digitalmars.hpp
@@ -33,7 +33,22 @@
 #if (__DMC__ >= 0x840)
 #define BOOST_HAS_DIRENT_H
 #define BOOST_HAS_STDINT_H
-#define BOOST_HAS_WINTHREADS
+#if _MT
+#  define BOOST_HAS_WINTHREADS
+#endif
+#endif
+
+#if (__DMC__ >= 0x847)
+#define BOOST_HAS_EXPM1
+#define BOOST_HAS_LOG1P
+#endif
+
+//
+// Is this really the best way to detect whether the std lib is in namespace std?
+//
+#include <cstddef>
+#if !defined(__STL_IMPORT_VENDOR_CSTD) && !defined(_STLP_IMPORT_VENDOR_CSTD)
+#  define BOOST_NO_STDC_NAMESPACE
 #endif
 
 
@@ -47,3 +62,4 @@
 #     error "Unknown compiler version - please run the configure tests and report the results"
 #  endif
 #endif
+