How do I point eliom-distillery to JavaScript primitives?

Js_of_ocaml’s manual explains here how to link external JavaScript code. However, I’m not trying to use js_of_ocaml directly, but rather to use the basic.ppx template from eliom-distillery. Is there a way to tell it to use external JS?

I was able to get it to work by manually modifying the Makefile:

JS_OF_ELIOM       := js_of_eliom -ppx


JS_OF_ELIOM       := js_of_eliom -jsopt +base/runtime.js -ppx

However, I would like to know if it’s possible to do this without modifying the Makefile, which is supposed to be discouraged.