Uglify changing order of declaration

[adam-ludgate]

Rails 4.2.11 project

I'm using JQuery among other things and when I do assets precompile with Uglify disabled, I get the Jquery code declared at the very top of the outputted application JS code (as expected)

//= require jquery
//= require jquery_ujs
//= require jquery-ui
//= require jquery-ui/effect.all
//= require bootstrap.min
//= require uSidebars.min
//= require moment
//= require bootstrap-datetimepicker
//= require bootstrap-toggle.min
//= require bootstrap-treeview
//= require utilities
etc...

However, when I enable uglify

config.assets.js_compressor = Uglifier.new(harmony: true,  compress: { unused: false })

After precompilation is completed, now my application's utilities JS code (which is dependent on Jquery) appears at the top of the outputted precompiled JS code and this causes my application to fail (unable to find Jquery declared)

Is this possibly an issue with sprockets/uglifier working together? Why would uglifier shuffle the order of the JS code to not match application.js ordering?