diff --git a/include/boost/config/compiler/vacpp.hpp b/include/boost/config/compiler/vacpp.hpp
index 1cd82dbd..377f295a 100644
--- a/include/boost/config/compiler/vacpp.hpp
+++ b/include/boost/config/compiler/vacpp.hpp
@@ -8,7 +8,7 @@
 //  Visual Age (IBM) C++ compiler setup:
 
 #define BOOST_NO_MEMBER_TEMPLATE_FRIENDS
-
+#define BOOST_NO_INCLASS_MEMBER_INITIALIZATION
 //
 // On AIX thread support seems to be indicated by _THREAD_SAFE:
 //