diff --git a/games/backgammon/backgammon/main.c b/games/backgammon/backgammon/main.c
index 8c93ed932204..e603346a0c0b 100644
--- a/games/backgammon/backgammon/main.c
+++ b/games/backgammon/backgammon/main.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: main.c,v 1.10 1999/07/14 22:46:21 hubertf Exp $	*/
+/*	$NetBSD: main.c,v 1.11 1999/07/19 00:33:58 hubertf Exp $	*/
 
 /*
  * Copyright (c) 1980, 1993
@@ -43,7 +43,7 @@ __COPYRIGHT("@(#) Copyright (c) 1980, 1993\n\
 #if 0
 static char sccsid[] = "@(#)main.c	8.1 (Berkeley) 5/31/93";
 #else
-__RCSID("$NetBSD: main.c,v 1.10 1999/07/14 22:46:21 hubertf Exp $");
+__RCSID("$NetBSD: main.c,v 1.11 1999/07/19 00:33:58 hubertf Exp $");
 #endif
 #endif				/* not lint */
 
@@ -99,6 +99,9 @@ main(argc, argv)
 	char    c;		/* non-descript character storage */
 	long    t;		/* time for random num generator */
 
+	/* revoke setgid privileges */
+	setregid(getgid(), getgid());
+
 	/* initialization */
 	bflag = 2;		/* default no board */
 	signal(SIGINT, getout);	/* trap interrupts */
diff --git a/games/backgammon/teachgammon/teach.c b/games/backgammon/teachgammon/teach.c
index c6c7c30a6526..b0130d260255 100644
--- a/games/backgammon/teachgammon/teach.c
+++ b/games/backgammon/teachgammon/teach.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: teach.c,v 1.8 1999/02/10 12:29:48 hubertf Exp $	*/
+/*	$NetBSD: teach.c,v 1.9 1999/07/19 00:34:00 hubertf Exp $	*/
 
 /*
  * Copyright (c) 1980, 1993
@@ -43,7 +43,7 @@ __COPYRIGHT("@(#) Copyright (c) 1980, 1993\n\
 #if 0
 static char sccsid[] = "@(#)teach.c	8.1 (Berkeley) 5/31/93";
 #else
-__RCSID("$NetBSD: teach.c,v 1.8 1999/02/10 12:29:48 hubertf Exp $");
+__RCSID("$NetBSD: teach.c,v 1.9 1999/07/19 00:34:00 hubertf Exp $");
 #endif
 #endif				/* not lint */
 
@@ -72,6 +72,9 @@ main(argc, argv)
 {
 	int     i;
 
+	/* revoke setgid privileges */
+	setregid(getgid(), getgid());
+
 	signal(SIGINT, getout);
 	if (tcgetattr(0, &old) == -1)	/* get old tty mode */
 		errexit("teachgammon(gtty)");