TypeError: store is undefined

Store:

Ext.define('Recruiting.store.Departments', {

extend: 'Ext.data.Store',

model: 'Recruiting.model.Department',

...

});

Controller:

Ext.define('Recruiting.controller.main.MainController', {

extend: 'Ext.app.ViewController',

stores : [ 'Departments' ],

alias: 'controller.main',

...

});

View:

Ext.define('Recruiting.view.main.Main', {

extend: 'Ext.container.Container',

controller: 'main',

...

items: [{

xtype: 'grid',

store: 'Departments',

title: 'Application Users',

...

}]

...

In Firebug I am seeing the error:

TypeError: store is undefined

TypeError: store is undefined