diff --git a/include/boost/config/compiler/visualc.hpp b/include/boost/config/compiler/visualc.hpp
index 083afa50..5cace357 100644
--- a/include/boost/config/compiler/visualc.hpp
+++ b/include/boost/config/compiler/visualc.hpp
@@ -310,6 +310,7 @@
 
 #if BOOST_CXX_VERSION >= 201703L
 #  define BOOST_ATTRIBUTE_UNUSED [[maybe_unused]]
+#  define BOOST_FALLTHROUGH [[fallthrough]]
 #endif
 
 #ifndef BOOST_COMPILER