diff --git a/app/Policies/TaskPolicy.php b/app/Policies/TaskPolicy.php
index 4213b50..d33e524 100644
--- a/app/Policies/TaskPolicy.php
+++ b/app/Policies/TaskPolicy.php
@@ -37,7 +37,7 @@ public function create(User $user): bool
      */
     public function update(User $user, Task $task): bool
     {
-        return $user->id == $task->user_id;
+        return $user->id == $task->user_id && $task->completed_at == null;
     }
 
     /**
@@ -47,4 +47,12 @@ public function delete(User $user, Task $task): bool
     {
         return $user->id == $task->user_id;
     }
+
+    /**
+     * Determine whether the user can delete the model.
+     */
+    public function complete(User $user, Task $task): bool
+    {
+        return $user->id == $task->user_id && $task->completed_at == null;
+    }
 }