diff --git a/src/Calendar.js b/src/Calendar.js
index 79b3ed55a..56680e053 100644
--- a/src/Calendar.js
+++ b/src/Calendar.js
@@ -569,7 +569,7 @@ class Calendar extends React.Component {
      * Optionally provide a function that returns an object of props to be applied
      * to the time-slot group node. Useful to dynamically change the sizing of time nodes.
      * ```js
-     * () => { style?: Object }
+     * (group: Date[]) => { style?: Object }
      * ```
      */
     slotGroupPropGetter: PropTypes.func,
diff --git a/src/TimeSlotGroup.js b/src/TimeSlotGroup.js
index fff057d30..80bd38009 100644
--- a/src/TimeSlotGroup.js
+++ b/src/TimeSlotGroup.js
@@ -14,7 +14,7 @@ export default class TimeSlotGroup extends Component {
       components: { timeSlotWrapper: Wrapper = BackgroundWrapper } = {},
     } = this.props
 
-	const groupProps = getters ? getters.slotGroupProp() : {}
+    const groupProps = getters ? getters.slotGroupProp(group) : {}
     return (
       <div className="rbc-timeslot-group" {...groupProps}>
         {group.map((value, idx) => {