grunt builds fail after upgrade to version 4.0.0

[arjopoldervaart]

If we upgrade the plugin from 3.0.0 to 4.0.0, we get the following error:

Could not get unknown property 'grunt_build' for project ':wachttijden-beheer-web' of type org.gradle.api.Project.

Our gradle build file contains:

grunt {
    workDir  = file("${project.projectDir}/DesignSource")
}

node {
    nodeProjectDir = file("${project.projectDir}/DesignSource")
}

// processes your package.json before running grunt build
grunt_build.dependsOn 'npmInstall'

war {
    dependsOn 'grunt_build'
}

Do we need to make any changes to our build scripts after upgrading? We changed nodeModulesDir to nodeProjectDir but made no other changes.

Regards,
Arjo Poldervaart