diff --git a/include/boost/mpl/aux_/config/overload_resolution.hpp b/include/boost/mpl/aux_/config/overload_resolution.hpp
index 5446227..8e7ed0d 100644
--- a/include/boost/mpl/aux_/config/overload_resolution.hpp
+++ b/include/boost/mpl/aux_/config/overload_resolution.hpp
@@ -21,7 +21,7 @@
 #include "boost/mpl/aux_/config/workaround.hpp"
 
 #if    !defined(BOOST_MPL_BROKEN_OVERLOAD_RESOLUTION) \
-    && !defined(BOOST_MPL_PREPROCESSING_MODE)
+    && !defined(BOOST_MPL_PREPROCESSING_MODE) \
     && (   BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x561)) \
         || BOOST_WORKAROUND(__MWERKS__, < 0x3001) \
         )