PHP - Calling a static method from the parent class

Question

I have the following class hierarchy: MDLUser inherits from MDLPersistentObject

In MDLPersistentObject I have a static method which returns an array. In MDLUser I override the static method so that it returns the MDLPersistentObject’s array, adds its own data, then returns the new array.

But when I call parent::myArrayReturningMethod() inside MDLUser it just returns MDLUser’s implementation (i.e. missing the array data from MDLPersistentObject. However, if I call it the bad practise way, MDLPersistentObject::myArrayReturningMethod(), then it returns what I expect.

Is parent:: not the correct late static binding method for calling a parent implementation of a static method?

If you’re wondering what my code looks like:

MDLPersistentObject’s method:

static public function Neo4j_Labels_In_Client( Everyman\Neo4j\Client $client )
{
    //
    //  Create a label called `MDLPersistentObject`
    //

    $mdlobject_label = $client->makeLabel( get_called_class() );


    //
    //  Return the label in an array
    //

    $labels = Array(
        $mdlobject_label
    );

    return $labels;
}

MDLUser’s method:

static public function Neo4j_Labels_In_Client( Everyman\Neo4j\Client $client )
{
    //
    //  Get the parent labels
    //

    $labels = parent::Neo4j_Labels_In_Client( $client );

    //
    //  Add the new labels
    //

    $user_label = $client->makeLabel( get_called_class() );

    array_push( $labels, $user_label );


    //
    //  Return labels
    //

    return $labels;
}