diff --git a/newlib/libc/include/time.h b/newlib/libc/include/time.h
index b7acf25e3a..d20e9ef044 100644
--- a/newlib/libc/include/time.h
+++ b/newlib/libc/include/time.h
@@ -228,7 +228,7 @@ int	   getdate_r (const char *, struct tm *);
 
 struct tm *gmtime (const time_t *_timer);
 
-#if __POSIX_VISIBLE
+#if __POSIX_VISIBLE || __ZEPHYR_VISIBLE
 struct tm *gmtime_r (const time_t *__restrict,
                      struct tm *__restrict);
 #endif