polymer: notifySplices fails to notify about changes in array of primitives

I have an array of Strings that’s being changed:

var model = {
    people: [
        "Alice",
        "Bob"
    ]
};
// ...
model.people[0] = "Anna";

So, I would like to notify my dom-bind about this change using notifySplices:

domBind.notifySplices('organization.people', [{
    index: 0,
    removed: removed,
    addedCount: 1,
    object: model.people,
    type: 'splice'
}]);

Live example here http://jsbin.com/kocowalimi/1/edit?html,console,output

In result, entire content of dom-repeat disappears and throws an error:

"TypeError: Cannot read property 'isPlaceholder' of undefined
    at dom-repeat.Polymer._detachInstance (http://polygit.org/components/polymer/polymer.html:4415:10)
    at dom-repeat.Polymer._detachAndRemoveInstance (http://polygit.org/components/polymer/polymer.html:4430:17)
    at dom-repeat.Polymer._applySplicesArrayOrder (http://polygit.org/components/polymer/polymer.html:4406:6)
    at dom-repeat.Polymer._render (http://polygit.org/components/polymer/polymer.html:4259:6)
    at Object.Debouncer.complete (http://polygit.org/components/polymer/polymer-mini.html:2099:15)
    at boundComplete (http://polygit.org/components/polymer/polymer-mini.html:2078:6)
    at Object.Polymer.Async._atEndOfMicrotask (http://polygit.org/components/polymer/polymer-mini.html:2055:1)
    at MutationObserver.window.MutationObserver.observe.characterData (http://polygit.org/components/polymer/polymer-mini.html:2070:15)"

If I change string names to objects like {name: "Alice"}.. it works, but I cannot change my database models, just to fit this UI.