diff --git a/sys/posix/include/arpa/inet.h b/sys/posix/include/arpa/inet.h
index bb10c61c9ee4..25779cbd6d5d 100644
--- a/sys/posix/include/arpa/inet.h
+++ b/sys/posix/include/arpa/inet.h
@@ -59,7 +59,7 @@ extern "C" {
  * @return  NULL, if @p size was smaller than needed
  * @return  NULL, if @p src or @p dst was NULL
  */
-const char *inet_ntop(int af, const void *restrict src, char *restrict dst,
+const char *inet_ntop(int af, const void *__restrict src, char *__restrict dst,
                       socklen_t size);
 
 /**