diff -up kbd-2.0.4/src/vlock/auth.c.orig kbd-2.0.4/src/vlock/auth.c
--- kbd-2.0.4/src/vlock/auth.c.orig	2016-12-19 16:01:51.000000000 +0100
+++ kbd-2.0.4/src/vlock/auth.c	2023-03-20 09:34:06.010036016 +0100
@@ -140,9 +140,9 @@ int get_password(pam_handle_t *pamh, con
 				fflush(stdout);
 				/*
 				 * EOF encountered on read?
-				 * If not on VT, check stdin.
+				 * Check stdin.
 				 */
-				if (is_vt || isatty(STDIN_FILENO)) {
+				if (isatty(STDIN_FILENO)) {
 					/* Ignore error. */
 					sleep(SHORT_DELAY);
 					break;