diff --git a/libcxx/include/__locale_dir/locale_base_api.h b/libcxx/include/__locale_dir/locale_base_api.h
index f973d95ef244d..79df29c7470d9 100644
--- a/libcxx/include/__locale_dir/locale_base_api.h
+++ b/libcxx/include/__locale_dir/locale_base_api.h
@@ -134,7 +134,9 @@
 //       (by providing global non-reserved names) and the new API. As we move individual platforms
 //       towards the new way of defining the locale base API, this should disappear since each platform
 //       will define those directly.
-#    include <__locale_dir/locale_base_api/ibm.h>
+#    ifdef __MVS__
+#      include <__locale_dir/locale_base_api/ibm.h>
+#    endif
 
 #    include <__locale_dir/locale_base_api/bsd_locale_fallbacks.h>