Clojurians Log v2

Hi! This is how I have my ClojureScript tests configured to run with figwheel:

:test-cljs {:extra-deps  {com.bhauman/figwheel-main {:mvn/version "0.2.18"}
                            org.slf4j/slf4j-nop       {:mvn/version "2.0.2"}}
              :extra-paths ["env/dev" "test" "target"]
              :main-opts
              ["-m" "hummi.build.test"
               "--compile-opts" "test.cljs.edn"
               "-fwo" "{:launch-js [\"firefox\" \"-headless\" :open-url] :ring-server-options {:port 9501}}"
               "-m" "hummi.test-runner"]}

And it mostly works great, the only issue is that Firefox keeps running after the tests complete. So I have to kill the process before I can run the tests again from the CLI. Does anyone have any tips for how to close Firefox gracefully after the test run?