Widget Icon Not Changing

[JustBrowsing90]

I've changed most of the widget icons with no issue but the "Latest Posts" widget icon just doesn't want to seem to change. I've got everything correct in the code so I have no idea why it's not changing.

Here's the code:

/*Latest Posts Widget Icon*/
[data-widget-key="forum_overview_new_posts"] h3.block-minorHeader:before {
    display: inline-block;
    padding-right: 5px;
    .m-faBase();
    .m-faContent(@fa-var-pen);
}