diff --git a/components/lib/calendar/Calendar.js b/components/lib/calendar/Calendar.js
index d62958ab8f..7de905c425 100644
--- a/components/lib/calendar/Calendar.js
+++ b/components/lib/calendar/Calendar.js
@@ -3660,13 +3660,13 @@ export const Calendar = React.memo(
                                     onClick: (event) => onMonthSelect(event, i),
                                     onKeyDown: (event) => onMonthCellKeydown(event, i),
                                     'data-p-disabled': !m.selectable,
-                                    'data-p-highlight': isMonthSelected(i)
+                                    'data-p-highlight': isMonthSelected(m)
                                 },
                                 ptm('month', {
                                     context: {
                                         month: m,
                                         monthIndex: i,
-                                        selected: isMonthSelected(i),
+                                        selected: isMonthSelected(m),
                                         disabled: !m.selectable
                                     }
                                 })