It seems that the three-argument version of `assoc' is too new.
(when (let ((term (frame-parameter nil 'tty-type)))
(and term (string-match "^xterm" term)))
(let* ((tty (frame-parameter nil 'tty))
- (old (assoc tty terminal-title-alist #'string=))
+ (old (assoc tty terminal-title-alist))
(new (format-mode-line frame-title-format)))
- (unless (and old (string= (cdr old) new))
+ (unless (and old (equal (cdr old) new))
(if old (rplacd old new)
(setq terminal-title-alist
(cons (cons tty new) terminal-title-alist)))