html2canvas converting visible part only

HTML

<script src="https://html2canvas.hertzen.com/dist/html2canvas.js"></script>
<p>Scroll around to see different results below: <button id="html2canvas">Export</button></p>

<div id="container">
    <div id="element">
    </div>
</div>

<p>Result:</p>
<div id="result"><div>

CSS

#container {
    height: 100px;
    overflow: auto;
}

#element {
    background-color: lightgrey;
}

JavaScript

// Fill element with many rows
for(var i = 0; i < 50; i++) {
    $('#element').append('<p>' + i + '</p>');
}

$('#html2canvas').click(function() {
    html2canvas($('#element'), {
        onrendered: function (canvas) {
        debugger;
            $('#result').html(canvas);
        }
    });
});