Hot reload @import css files

I’m using juliancwirko:postcss to @import css files. It’s set up like this in package.json

"postcss": {
    "plugins": {
      "postcss-easy-import": {}
    }
  }

I’m importing a file into my /client/main.css like this:

@import '../imports/ui/css/ds.css';

ds.css is importing several files like this:

@import '_minireset.css'; 
@import '_fonts.css'; 
@import '_base.css'; 
/* ...etc */

When I make a change to one of the files imported in ds.css , e.g. _base.css , the change isn’t hot reloaded. Is anyone aware of a way to set things up so that the imported files are watched and hot reloaded when a change is made?