diff --git a/cli.c b/cli.c
index 2f68bb7..d0c2348 100644
--- a/cli.c
+++ b/cli.c
@@ -30,7 +30,8 @@ extern const char *__progname;
 static void
 usage(void)
 {
-	fprintf(stderr, "Usage: %s [-H counter] SECRET\n", __progname);
+	fprintf(stderr, "Usage:\n"
+	    "    %s [-h HMAC] [-H counter | -T counter] SECRET\n", __progname);
 	exit(1);
 }
 
@@ -41,10 +42,12 @@ main(int argc, char *argv[])
 	uint64_t counter;
 	int32_t r;
 	int ch, do_hotp;
+	enum otp_hmac hmac;
 
 	counter = 0;
 	do_hotp = 0;
-	while ((ch = getopt(argc, argv, "H:T:")) != -1) {
+	hmac = OTP_HMAC_SHA1;
+	while ((ch = getopt(argc, argv, "H:h:T:")) != -1) {
 		switch (ch) {
 		case 'H':
 			counter = mystrtonum(optarg, 0, LLONG_MAX, &errstr);
@@ -52,6 +55,16 @@ main(int argc, char *argv[])
 				errx(1, "counter is %s: %s", errstr, optarg);
 			do_hotp = 1;
 			break;
+		case 'h':
+			if (strcasecmp(optarg, "sha1") == 0)
+				hmac = OTP_HMAC_SHA1;
+			else if (strcasecmp(optarg, "sha256") == 0)
+				hmac = OTP_HMAC_SHA256;
+			else if (strcasecmp(optarg, "sha512") == 0)
+				hmac = OTP_HMAC_SHA512;
+			else
+				usage();
+			break;
 		case 'T':
 			counter = mystrtonum(optarg, 0, LLONG_MAX, &errstr);
 			if (errstr != NULL)
@@ -69,13 +82,12 @@ main(int argc, char *argv[])
 		usage();
 
 	if (do_hotp) {
-		r = hotp(OTP_HMAC_SHA1, argv[0], strlen(argv[0]), counter, 6);
+		r = hotp(hmac, argv[0], strlen(argv[0]), counter, 6);
 		if (r == -1)
 			errx(1, "couldn't calculate HOTP");
 		printf("%0*" PRId32 "\n", 6, r);
 	} else {
-		r = totp(OTP_HMAC_SHA1, argv[0], strlen(argv[0]), counter,
-		    30, 8);
+		r = totp(hmac, argv[0], strlen(argv[0]), counter, 30, 8);
 		if (r == -1)
 			errx(1, "couldn't calculate TOTP");
 		printf("%0*" PRId32 "\n", 8, r);