diff --git a/include/boost/config/compiler/vacpp.hpp b/include/boost/config/compiler/vacpp.hpp
index 89d5e7f6..0cc8dc2c 100644
--- a/include/boost/config/compiler/vacpp.hpp
+++ b/include/boost/config/compiler/vacpp.hpp
@@ -26,6 +26,7 @@
 #endif
 
 #if (__IBMCPP__ <= 600) || !defined(BOOST_STRICT_CONFIG)
+#  define BOOST_NO_INCLASS_MEMBER_INITIALIZATION
 #endif
 
 //