Use @Grab in Jenkins pipeline script

Question

We are trying to use some custom helper functions from a .jar library in our Jenkinsfile. To achieve this, we want to use the @Grab annotation from groovy/grape. Our Jenkinsfile looks like this:

@Grab('com.company:jenkins-utils:1.0')
import com.company.jenkinsutils.SomeClass

pipeline {
    ...
}

When trying to run the pipeline, we get the following error message:

java.lang.RuntimeException: No suitable ClassLoader found for grab

I already tried specifying @GrabConfig(systemClassLoader = true), however to no success. I suppose is has to do with the pipeline scripts running in the sandbox mode? Is there any way to make this work?