classList.js does not work if loaded after DOMContentLoaded

[tmb-github]

I defer all of my JavaScript until after DOMContentLoaded. The classList.js polyfill is not accessible unless it is loaded at or before document.readyState === "loading". How can this be overcome?

[englishextra]

you can do smth like this at the bottom of the body of your page:

loadJS("./polyfills.js",loadJS("./bundle.js"));

see here

DOMContentLoaded is tricky:
see here