Dependency not loading, seems to be a naming issue?

[4imble]

Hello all,

I am attempting to transpile a file (it comes with it's own transpiled version but i wanted to be able to work with the es6 version and transpile it myself):
https://github.com/cbcrc/knockout-dragula/blob/master/knockout-dragula.js

I have set up gulp like so:

gulp.task('transpile', function() {
    return gulp.src('Dependencies/lib/knockout-dragula/knockout-dragula.js')
        .pipe(plumber())
        .pipe(babel({
            presets: ['es2015'],
            plugins: ["transform-es2015-modules-umd"]
        }))
        .pipe(gulp.dest('Scripts/generated'));
});

The file that it is generating looks starts like this:

(function (global, factory) {
    if (typeof define === "function" && define.amd) {
        define(['exports', 'knockout', 'dragula'], factory);
    } else if (typeof exports !== "undefined") {
        factory(exports, require('knockout'), require('dragula'));
    } else {
        var mod = {
            exports: {}
        };
        factory(mod.exports, global.knockout, global.dragula);
        global.knockoutDragula = mod.exports;
    }
})(this, function (exports, _knockout, _dragula) {

The problem i am encountering and i am not sure if it is ignorance on my part but _knockout is coming through undefined.
I looked at the transpiled file that they supply and this looks like this at the start:
https://github.com/cbcrc/knockout-dragula/blob/master/dist/knockout-dragula.js

(function (global, factory) {
  if (typeof define === 'function' && define.amd) {
    define(['exports', 'module', 'knockout', 'dragula'], factory);
  } else if (typeof exports !== 'undefined' && typeof module !== 'undefined') {
    factory(exports, module, require('knockout'), require('dragula'));
  } else {
    var mod = {
      exports: {}
    };
    factory(mod.exports, mod, global.ko, global.dragula);
    global.knockoutDragula = mod.exports;
  }
})(this, function (exports, module, _knockout, _dragula) {

After some debugging the breaking difference seems to be this:
factory(mod.exports, global.knockout , global.dragula);//broken
vs.
factory(mod.exports, mod, global.ko, global.dragula); //works

If i change my version to global.ko it works.

Am i doing something wrong, do i need to do something extra so that it knows to look for knockout inside global.ko and not global.knockout?

Many thanks.
4imble