diff --git a/ghost/admin/app/controllers/settings/membership.js b/ghost/admin/app/controllers/settings/membership.js
index b0d15b0c95..0da6ada778 100644
--- a/ghost/admin/app/controllers/settings/membership.js
+++ b/ghost/admin/app/controllers/settings/membership.js
@@ -104,7 +104,7 @@ export default class MembersAccessController extends Controller {
 
     @action
     async membersSubscriptionAccessChanged() {
-        const [oldValue] = this.settings.changedAttributes().membersSignupAccess;
+        const oldValue = this.settings.changedAttributes().membersSignupAccess?.[0];
 
         if (oldValue === 'none') {
             // when saved value is 'none' the server won't inject the portal script