diff --git a/be/app/Http/Resources/SubTaskResource.php b/be/app/Http/Resources/SubTaskResource.php
index c6ce5f5..7ab1840 100644
--- a/be/app/Http/Resources/SubTaskResource.php
+++ b/be/app/Http/Resources/SubTaskResource.php
@@ -29,6 +29,7 @@ class SubTaskResource extends JsonResource
             'duration' => $this->estimated_time,
             'spent_time' => $this->tracked_time,
             'deadline' => $this->deadline,
+            'master_task_deadline' => $this->mastertask->deadline,
             'is_finished' => $this->is_finished,
             'timeblocks' => TimeblockResource::collection($this->timeblocks),
             'timesheets' => TimesheetResource::collection($this->timesheets),