diff --git a/cli.c b/cli.c
index a606642..5d060f4 100644
--- a/cli.c
+++ b/cli.c
@@ -45,12 +45,12 @@ main(int argc, char *argv[])
 	uint64_t counter;
 	unsigned int step;
 	int32_t r;
-	int ch, digits, do_hotp;
+	int ch, digits, do_hotp, do_totp;
 	enum otp_hmac hmac;
 
 	counter = (uint64_t)time(NULL);
 	digits = 6;
-	do_hotp = 0;
+	do_hotp = do_totp = 0;
 	hmac = OTP_HMAC_SHA1;
 	step = 30;
 	while ((ch = getopt(argc, argv, "d:H:h:s:T:")) != -1) {
@@ -85,7 +85,7 @@ main(int argc, char *argv[])
 			counter = mystrtonum(optarg, 0, LLONG_MAX, &errstr);
 			if (errstr != NULL)
 				errx(1, "counter is %s: %s", errstr, optarg);
-			do_hotp = 0;
+			do_totp = 1;
 			break;
 		default:
 			usage();
@@ -94,6 +94,11 @@ main(int argc, char *argv[])
 	argc -= optind;
 	argv += optind;
 
+	if (do_hotp && do_totp) {
+		warnx("-H and -T are mutually exclusive");
+		usage();
+	}
+
 	if (argc != 1)
 		usage();