diff --git a/lib/editor/components/timetable/CalendarSelect.js b/lib/editor/components/timetable/CalendarSelect.js
index 73ff815ec..e2442da7c 100644
--- a/lib/editor/components/timetable/CalendarSelect.js
+++ b/lib/editor/components/timetable/CalendarSelect.js
@@ -104,7 +104,7 @@ export default class CalendarSelect extends Component<Props> {
   _getOptions = (): Array<CalendarOption> => {
     const {activePattern, calendars, exceptionBasedCalendars, tripCounts, trips} = this.props
     const patternId = activePattern && activePattern.patternId
-    let calendarOptions: Array<CalendarOption> = calendars && activePattern
+    const calendarBasedOptions: Array<CalendarOption> = calendars && activePattern
       ? calendars
         .map(calendar => ({
           label: calendar.description || calendar.service_id,
@@ -129,7 +129,7 @@ export default class CalendarSelect extends Component<Props> {
     }))
 
     // $FlowFixMe: we need two types of options
-    calendarOptions = calendarOptions.concat(exceptionBasedCalendarOptions)
+    const calendarOptions = calendarBasedOptions.concat(exceptionBasedCalendarOptions)
 
     return calendarOptions
       .sort((a, b) => {