diff --git a/app/src/main/kotlin/com/simplemobiletools/calendar/pro/extensions/Context.kt b/app/src/main/kotlin/com/simplemobiletools/calendar/pro/extensions/Context.kt
index a73d52ab1..5679bba2b 100644
--- a/app/src/main/kotlin/com/simplemobiletools/calendar/pro/extensions/Context.kt
+++ b/app/src/main/kotlin/com/simplemobiletools/calendar/pro/extensions/Context.kt
@@ -659,6 +659,7 @@ fun Context.getDatesWeekDateTime(date: DateTime): String {
 }
 
 fun Context.isTaskCompleted(event: Event): Boolean {
+    if (event.id == null) return false
     val task = completedTasksDB.getTaskWithIdAndTs(event.id!!, event.startTS) ?: return false
     return task.flags and FLAG_TASK_COMPLETED != 0
 }