diff --git a/cfg/boost.cfg b/cfg/boost.cfg
index 0d126a3a6..46e5a9eb0 100644
--- a/cfg/boost.cfg
+++ b/cfg/boost.cfg
@@ -12,6 +12,7 @@
   <define name="BOOST_TYPEOF_REGISTER_TYPE(x)" value=""/>
   <define name="BOOST_TYPEOF_REGISTER_TEMPLATE(x, params)" value=""/>
   <define name="BOOST_PP_LIST_FOR_EACH(macro, data, list)" value=""/>
+  <define name="BOOST_PP_CAT(a, b)" value=""/>
   <!-- https://www.boost.org/doc/libs/master/doc/html/foreach.html -->
   <define name="BOOST_FOREACH(A,B)" value="for (A: B)"/>
   <!-- https://www.boost.org/doc/libs/master/libs/config/doc/html/boost_config/boost_macro_reference.html -->