node.js: fixing ev_ref/ev_unref warning

I have a Node.JS extension that's causing warnings in Node.JS 0.8.4:

WARNING: ev_ref is deprecated, use uv_ref
WARNING: ev_unref is deprecated, use uv_unref

I'd like to patch the extension to avoid these warnings but I can't find any information on ev_ref/uv_ref.

The warning is probably caused by lines like these:

  ev_ref(EV_DEFAULT_UC);
  ev_unref(EV_DEFAULT_UC);

(no other variants found).

What's the equivalent uv_[un]ref() call and are there any compatibility issues I should know?