How to get the actual class of the annotation?

This is run by a Spring Interceptor from ProceedingJoinPoint

fun myMethod(methodSignature : MethodSignature){
    val params : Array<Parameter>? = methodSignature.method.parameters

    if(params != null && params.isNotEmpty){
        params.forEachIndexed{
            index, parameter ->
            for(annotation in parameter.annotations){
                println(AopUtils.getTargetClass(annotation))
            }
        }
    }

}

Currently, I am only seeing Proxy classes (eg com.sun.proxy.$Proxy123 and not MyAnnotation) in the println. How to get the actual annotation class? Yes, the annotation was written in Kotlin.