diff --git a/newlib/libc/include/locale.h b/newlib/libc/include/locale.h
index 4fb78755e..446dbd9d4 100644
--- a/newlib/libc/include/locale.h
+++ b/newlib/libc/include/locale.h
@@ -71,10 +71,10 @@ struct _reent;
 char *_EXFUN(_setlocale_r,(struct _reent *, int, const char *));
 struct lconv *_EXFUN(_localeconv_r,(struct _reent *));
 
-locale_t _newlocale_r (struct _reent *, int, const char *, locale_t);
-void _freelocale_r (struct _reent *, locale_t);
-locale_t _duplocale_r (struct _reent *, locale_t);
-locale_t _uselocale_r (struct _reent *, locale_t);
+locale_t _newlocale_r (struct _reent *, int, const char *, struct __locale_t *);
+void _freelocale_r (struct _reent *, struct __locale_t *);
+locale_t _duplocale_r (struct _reent *, struct __locale_t *);
+locale_t _uselocale_r (struct _reent *, struct __locale_t *);
 
 #ifndef _REENT_ONLY