[Vuejs]-Why is this :class="{}" not working? vueJs

Replace

<li class="li-item"
    v-for="employee in employees" :key="employee.id"
    :class="{employee.checked: isChecked}">

with

<li class="li-item"
    v-for="employee in employees" :key="employee.id"
    :class="{isChecked: employee.checked}">