diff --git a/cli.c b/cli.c
index b44a482..2f68bb7 100644
--- a/cli.c
+++ b/cli.c
@@ -72,13 +72,13 @@ main(int argc, char *argv[])
 		r = hotp(OTP_HMAC_SHA1, argv[0], strlen(argv[0]), counter, 6);
 		if (r == -1)
 			errx(1, "couldn't calculate HOTP");
-		printf("%" PRId32 "\n", r);
+		printf("%0*" PRId32 "\n", 6, r);
 	} else {
 		r = totp(OTP_HMAC_SHA1, argv[0], strlen(argv[0]), counter,
 		    30, 8);
 		if (r == -1)
 			errx(1, "couldn't calculate TOTP");
-		printf("%" PRId32 "\n", r);
+		printf("%0*" PRId32 "\n", 8, r);
 	}
 
 	return 0;