Can't bundle install when 'jekyll-related-posts' is listed in Gemfile

[bildungsroman]

I'm trying to use the jekyll-related-posts plugin, but when I run bundle install with it listed in the Gemfile, I get this readout:

Bundler could not find compatible versions for gem "liquid":
  In snapshot (Gemfile.lock):
    liquid (= 4.0.0)

  In Gemfile:
    jekyll (= 3.8.3) was resolved to 3.8.3, which depends on
      liquid (~> 4.0)

    jekyll-related-posts was resolved to 0.1.2, which depends on
      liquid (~> 3.0)

Running `bundle update` will rebuild your snapshot from scratch, using only
the gems in your Gemfile, which may resolve the conflict.

When I take it out, everything else installs fine. I'm on Jekyll 3.8.3.

[atjiu]

exec bundle update It will be fine