testTask.setClasspath(
                yamlCompatTestSourceSet.getRuntimeClasspath()
                    // remove the "normal" api and tests
                    .minus(project.files(yamlTestSourceSet.getOutput().getResourcesDir()))
                    .minus(project.files(originalYamlSpecsDir))
                    .minus(project.files(originalYamlTestsDir))
            );
            // run compatibility tests after "normal" tests