diff --git a/app/Ninja/Transformers/ActivityTransformer.php b/app/Ninja/Transformers/ActivityTransformer.php
index 5c0ea3e3ab41..f8ffa38c5985 100644
--- a/app/Ninja/Transformers/ActivityTransformer.php
+++ b/app/Ninja/Transformers/ActivityTransformer.php
@@ -35,6 +35,7 @@ class ActivityTransformer extends EntityTransformer
             'expense_id' => $activity->expense_id ? $activity->expense->public_id : null,
             'is_system' => $activity->is_system ? (bool) $activity->is_system : null,
             'contact_id' => $activity->contact_id ? $activity->contact->public_id : null,
+            'task_id' => $activity->task_id ? $activity->task->public_id : null,
         ];
     }
 }