diff --git a/usr.bin/mail/aux.c b/usr.bin/mail/aux.c
index fa820b4a94b..e764aacd000 100644
--- a/usr.bin/mail/aux.c
+++ b/usr.bin/mail/aux.c
@@ -70,7 +70,7 @@ savestr(str)
 /*
  * Make a copy of new argument incorporating old one.
  */
-char *
+static char *
 save2str(str, old)
 	char *str, *old;
 {