diff --git a/include/boost/config/select_stdlib_config.hpp b/include/boost/config/select_stdlib_config.hpp
index 0baca79a..8db778c8 100644
--- a/include/boost/config/select_stdlib_config.hpp
+++ b/include/boost/config/select_stdlib_config.hpp
@@ -66,7 +66,7 @@
 // MSL standard lib:
 #  define BOOST_STDLIB_CONFIG "boost/config/stdlib/msl.hpp"
 
-#elif defined(__IBMCPP__) && defined(__COMPILER_VER__)
+#elif defined(__IBMCPP__) && defined(__COMPILER_VER__) && defined(__MVS__)
 // IBM z/OS XL C/C++
 #  define BOOST_STDLIB_CONFIG "boost/config/stdlib/xlcpp_zos.hpp"