#include <stdbool.h>
-#if HAVE_STDIO_EXT_H
-# include <stdio_ext.h>
-#endif
-#if !HAVE___FSETLOCKING
+#if HAVE_DECL___FSETLOCKING && HAVE___FSETLOCKING
+# if HAVE_STDIO_EXT_H
+# include <stdio_ext.h>
+# endif
+#else
# define __fsetlocking(stream, type) /* empty */
#endif