savehist-mode: Lisp error: (void-variable pell-buffer)

I am using GNU Emacs 26.3 in macOS. For (savehist-mode 1) I keep getting following error:

Debugger entered--Lisp error: (void-variable pell-buffer)
  signal(void-variable (pell-buffer))
  savehist-mode(1)
  eval-buffer(#<buffer  *load*> nil "/Users/alper/.emacs" nil t)  ; Reading at buffer position 98709
  load-with-code-conversion("/Users/alper/.emacs" "/Users/alper/.emacs" t t)
  load("~/.emacs" t t)
  #f(compiled-function () #<bytecode 0x400d1a6d>)()
  command-line()
  normal-top-level()

What may be the main cause of this error and how can I solve it?