Flexbox is not taking full height in IE

html,
body {
  margin: 0;
  padding: 0;
}

.flex-wrap {
  display: flex;
  display: -ms-flex;
  min-height: 100vh;
  background: #ddd;
}

.child {
  border: 1px solid;
  flex: 1 1;
}

<div>
  <div class="flex-wrap">
    <div class="child">
      Lorem ipsum dolor sit amet, consectetur adipisicing elit. Quam enim, soluta dolor dolorum debitis eum id architecto iste similique eaque cum saepe, aperiam error reiciendis recusandae incidunt nihil, cupiditate quae.
    </div>
    <div class="child">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Eaque iste itaque provident ex debitis numquam minima, ratione quaerat sapiente eveniet cum quia quisquam aut deleniti explicabo ipsam nulla asperiores voluptatum?</div>
  </div>
</div>