diff --git a/usr.bin/id/id.c b/usr.bin/id/id.c
--- a/usr.bin/id/id.c
+++ b/usr.bin/id/id.c
@@ -144,6 +144,8 @@
 
 	if (iswhoami && argc > 0)
 		usage();
+	if ((cflag || Aflag || Mflag) && argc > 0)
+		usage();
 
 	switch(Aflag + Gflag + Mflag + Pflag + gflag + pflag + uflag) {
 	case 1: