Gatsby.js with Wordpress installation in subdirectory

I've beem building a Gatsby.js website with a headless CMS, using the previous WordPress version of the site to supply the content. Everything was working great until I moved the WordPress installation from the root to a subfolder. The GraphQL queries stopped working and the site won't build anymore.

In the gatsby-source-wordpress plugin documentation there is no specification how to proceed in this case. I've tried changing both the baseUrl and the includedRoutes options, but to no avail. The queries only work if the WordPress instalation is the domain root.

Here's a sample of my gatsby-config.js file with the plugin parameters:

module.exports = {
  plugins: [
      resolve: 'gatsby-source-wordpress',
      options: {
        baseUrl: '',
        hostingWPCOM: false,
        protocol: 'http',
        useACF: true,
        verboseOutput: false,
        includedRoutes: [

Any help will be most welcome. Cheers!