diff --git a/tty-keys.c b/tty-keys.c
index c90eb71e..cb3b4e03 100644
--- a/tty-keys.c
+++ b/tty-keys.c
@@ -734,7 +734,8 @@ tty_keys_device(struct tty *tty, const char *buf, size_t len, size_t *size)
 		a = b = 0;
 
 	log_debug("received xterm version %u", b);
-	tty_set_version(tty, b);
+	if (b < 500)
+		tty_set_version(tty, b);
 
 	return (0);
 }