-# define duplocale(l) \
- (GL_LINK_WARNING ("duplocale is buggy on some glibc systems - " \
- "use gnulib module duplocale for portability"), \
- duplocale (l))
+# if HAVE_RAW_DECL_DUPLOCALE
+_GL_WARN_ON_USE (duplocale, "duplocale is buggy on some glibc systems - "
+ "use gnulib module duplocale for portability");
+# endif