Workaround: 

.rtsDropClueLeft {
    margin: -0.5em 0 0 -0.75em;
}

    .rtsDropClueLeft:before {
        content: "\e005";
    }

.rtsDropClueRight {
    margin: -0.5em 0 0 -0.25em;
}

    .rtsDropClueRight:before {
        content: "\e007";
    }