Trying to make a plugin I messed up the classpaths

I have integration tests in a separate folder (integrationTest) so I am trying to make a plugin that I can use to run them.
However I messed up the classpath somehow in a very weird way…

Normally files in resources-folder are accessible in this order;

  1. integrationTest/resources
  2. test/resources
  3. main/resources
  4. resources in dependencies

So if the same messages.properties exist in both 1 and 3, the first one will be loaded.

However, in my case the order looks like this.

  1. integrationTest/resources
  2. resources in dependencies
  3. test/resources
  4. main/resources

So in this case the properties file is loaded from a dependecny-jar before the one in main/resources…

This is my integrationTestPlugin.gradle

sourceSets {
  integrationTest {
    java.srcDir file(integrationTestSourceDir)
    resources.srcDir file(integrationTestResourceDir)
    compileClasspath += main.output + test.output
    runtimeClasspath += main.output + test.output
  }
}

configurations {
  integrationTestImplementation.extendsFrom testImplementation
}

task integrationTest(type: Test) {
  useJUnitPlatform()

  description = 'Runs integration test'
  group = 'verification'

  testClassesDirs = sourceSets.integrationTest.output.classesDirs
  classpath = sourceSets.integrationTest.runtimeClasspath
  include '**/*IT.class'
}

The gradle.properties

integrationTestSourceDir=src/integrationTest/java
integrationTestResourceDir=src/integrationTest/resources

Did I specify runtimeClasspath wrong?

I use v7.4.1 on Linux, if it matters.

Thanks.