diff --git a/src/bin/psql/startup.c b/src/bin/psql/startup.c
index 210be63f67c..4a4ce82e595 100644
--- a/src/bin/psql/startup.c
+++ b/src/bin/psql/startup.c
@@ -552,15 +552,17 @@ parse_psql_options(int argc, char *argv[], struct adhoc_opts * options)
 				options->single_txn = true;
 				break;
 			case '?':
-				/* Actual help option given */
-				if (strcmp(argv[optind - 1], "--help") == 0 || strcmp(argv[optind - 1], "-?") == 0)
+				if (optind <= argc &&
+					(strcmp(argv[optind - 1], "--help") == 0 ||
+					 strcmp(argv[optind - 1], "-?") == 0))
 				{
+					/* actual help option given */
 					usage();
 					exit(EXIT_SUCCESS);
 				}
-				/* unknown option reported by getopt */
 				else
 				{
+					/* getopt error (unknown option or missing argument) */
 					fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
 							pset.progname);
 					exit(EXIT_FAILURE);