diff --git a/include/boost/config/auto_link.hpp b/include/boost/config/auto_link.hpp
index e36d06a0..13cbad43 100644
--- a/include/boost/config/auto_link.hpp
+++ b/include/boost/config/auto_link.hpp
@@ -151,11 +151,16 @@ BOOST_LIB_VERSION:    The Boost version, in the form x_y, for Boost version x.y.
      // vc10:
 #    define BOOST_LIB_TOOLSET "vc100"
 
-#  elif defined(BOOST_MSVC)
+#  elif defined(BOOST_MSVC) && (BOOST_MSVC < 1800)
 
      // vc11:
 #    define BOOST_LIB_TOOLSET "vc110"
 
+#  elif defined(BOOST_MSVC)
+
+     // vc12:
+#    define BOOST_LIB_TOOLSET "vc120"
+
 #  elif defined(__BORLANDC__)
 
      // CBuilder 6:
@@ -421,3 +426,4 @@ BOOST_LIB_VERSION:    The Boost version, in the form x_y, for Boost version x.y.
 #  undef BOOST_DYN_LINK
 #endif
 
+
diff --git a/include/boost/config/compiler/visualc.hpp b/include/boost/config/compiler/visualc.hpp
index 11587f74..412de25e 100644
--- a/include/boost/config/compiler/visualc.hpp
+++ b/include/boost/config/compiler/visualc.hpp
@@ -310,8 +310,10 @@
 #     define BOOST_COMPILER_VERSION 9.0
 #   elif _MSC_VER < 1700
 #     define BOOST_COMPILER_VERSION 10.0
-#   elif _MSC_VER < 1800
+#   elif _MSC_VER < 1800 
 #     define BOOST_COMPILER_VERSION 11.0
+#   elif _MSC_VER < 1900
+#     define BOOST_COMPILER_VERSION 12.0
 #   else
 #     define BOOST_COMPILER_VERSION _MSC_VER
 #   endif
@@ -321,8 +323,8 @@
 #endif
 
 //
-// last known and checked version is 1700 (VC11, aka 2011):
-#if (_MSC_VER > 1700)
+// last known and checked version is 1800.20617 (VC12 Preview, aka 2013 Preview):
+#if (_MSC_VER > 1800 && _MSC_FULL_VER > 180020617)
 #  if defined(BOOST_ASSERT_CONFIG)
 #     error "Unknown compiler version - please run the configure tests and report the results"
 #  else