diff --git a/website/server/models/task.js b/website/server/models/task.js
index 6d4143e80d..1fbe351e18 100644
--- a/website/server/models/task.js
+++ b/website/server/models/task.js
@@ -40,7 +40,7 @@ export let TaskSchema = new Schema({
   challenge: {
     id: {type: String, ref: 'Challenge', validate: [validator.isUUID, 'Invalid uuid.']}, // When set (and userId not set) it's the original task
     taskId: {type: String, ref: 'Task', validate: [validator.isUUID, 'Invalid uuid.']}, // When not set but challenge.id defined it's the original task
-    broken: {type: String, enum: ['CHALLENGE_DELETED', 'TASK_DELETED', 'UNSUBSCRIBED', 'CHALLENGE_CLOSED']},
+    broken: {type: String, enum: ['CHALLENGE_DELETED', 'TASK_DELETED', 'UNSUBSCRIBED', 'CHALLENGE_CLOSED', 'CHALLENGE_TASK_NOT_FOUND']}, // CHALLENGE_TASK_NOT_FOUND comes from v3 migration
     winner: String, // user.profile.name of the winner
   },