Variable from other file not found

I have following gulp file

elixir(function(mix) {
    mix.less('app.less')
    .browserify('app.js')
    .scriptsIn('resources/assets/admin','public/js/admin.js')
    .version(['public/js/admin.js','public/js/app.js']);
});

app.js // Works

var numeral = require('numeral');
var testing = numeral(1000).format('0,0');
console.log(testing );

admin app.js // Not found numeral variable

var testing2= numeral(2000).format('0,0');
console.log(testing2);

layout included first app.js, then admin/js/app.js

<script type="text/javascript" src="{{ elixir('js/app.js') }}"></script>
<script type="text/javascript" src="{{ elixir('js/admin.js') }}"></script>

Why js/admin.js can't use numeral variable? With basic javascript files this works.