What is the standard way of loading mapping plugin in require.js ?

Below is my config.js (require.js config file)

require.config({

// Initialize the application with the main application file.
deps:["app"],

paths:{
    // JavaScript folders.
    libs:"lib",
    plugins:"lib/plugin",
    templates:"../templates",

    // Libraries.
    jquery:"lib/jquery-1.7.2.min",
    underscore:"lib/lodash",
    text:'text',
    order:'order',
    knockout:"lib/knockout",
    knockoutmapping:"lib/plugin/knockout-mapping"

},

shim:{ underscore:{ exports:'_' },

    knockout:{
        deps:["jquery"],
        exports:"knockout"
    }
 }

}

In my view model

define(['knockout', 'knockoutmapping'], function(ko, mapping) {
}

However, mapping is not bound to ko.mapping. Any pointers/suggestions would be appreciated.

Thanks, Ravi