diff --git a/coreutils/date.c b/coreutils/date.c
index d70957cf6..a1a004d45 100644
--- a/coreutils/date.c
+++ b/coreutils/date.c
@@ -250,7 +250,10 @@ int date_main(int argc UNUSED_PARAM, char **argv)
 		ts.tv_sec = statbuf.st_mtime;
 #if ENABLE_FEATURE_DATE_NANO
 		ts.tv_nsec = statbuf.st_mtim.tv_nsec;
-		/* some toolchains use .st_mtimensec instead of st_mtim.tv_nsec */
+		/* Some toolchains use .st_mtimensec instead of st_mtim.tv_nsec.
+		 * If you need #define SVID_SOURCE 1 to enable st_mtim.tv_nsec,
+		 * drop a mail to project mailing list please
+		 */
 #endif
 	} else {
 #if ENABLE_FEATURE_DATE_NANO