This test case throws an exception "! >= !": <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"> <g transform="translate(150 150) scale(0.5)"> <path d="M-2 50h4v -90h4l -6 -10 -6 10h4z" fill="blue"> <animateTransform attributeName="transform" attributeType="XML" type="scale" fill="freeze" by="1" dur="0.5s" repeatCount="3" accumulate="sum"/> </path> </g> </svg>