diff --git a/newlib/libc/include/inttypes.h b/newlib/libc/include/inttypes.h
index 570ed0481..417ff224c 100644
--- a/newlib/libc/include/inttypes.h
+++ b/newlib/libc/include/inttypes.h
@@ -321,7 +321,7 @@ extern "C" {
 #endif
 
 extern intmax_t  imaxabs(intmax_t);
-extern imaxdiv_t imaxdiv(intmax_t numer, intmax_t denomer);
+extern imaxdiv_t imaxdiv(intmax_t __numer, intmax_t __denomer);
 extern intmax_t  strtoimax(const char *__restrict, char **__restrict, int);
 extern intmax_t  _strtoimax_r(struct _reent *, const char *__restrict, char **__restrict, int);
 extern uintmax_t strtoumax(const char *__restrict, char **__restrict, int);