Sorry if this has been fixed since 21.0-b54 (custom-v1.9960-x) (defcustom cw-symbol-list nil "Test" :type '(repeat (sexp :value nil))) (defcustom cw-string-list nil "Test" :type '(repeat (sexp :value "nil"))) The custom buffer look like the following when adding elements to these list: Cw Symbol List: * [INS] [DEL] Lisp expression: "nil" [INS] Cw String List: * [INS] [DEL] Lisp expression: "\"nil\"" [INS] When setting the variables, their values look like ("nil") and ("\"nil\"") Unfortunatly, I just start using custom, so I cannot send a patch. - Christoph