diff --git a/app/Model/Subtask.php b/app/Model/Subtask.php
index 65fa0f0ce..a869ae912 100644
--- a/app/Model/Subtask.php
+++ b/app/Model/Subtask.php
@@ -227,6 +227,18 @@ class Subtask extends Base
         return $result;
     }
 
+    /**
+     * Close all subtasks of a task
+     *
+     * @access public
+     * @param  integer  $task_id
+     * @return boolean
+     */
+    public function closeAll($task_id)
+    {
+        return $this->db->table(self::TABLE)->eq('task_id', $task_id)->update(array('status' => self::STATUS_DONE));
+    }
+
     /**
      * Get subtasks with consecutive positions
      *
diff --git a/app/Model/TaskStatus.php b/app/Model/TaskStatus.php
index 30a65e1e0..3f62667ca 100644
--- a/app/Model/TaskStatus.php
+++ b/app/Model/TaskStatus.php
@@ -62,6 +62,7 @@ class TaskStatus extends Base
      */
     public function close($task_id)
     {
+        $this->subtask->closeAll($task_id);
         return $this->changeStatus($task_id, Task::STATUS_CLOSED, time(), Task::EVENT_CLOSE);
     }
 
@@ -113,7 +114,7 @@ class TaskStatus extends Base
     }
 
     /**
-     * Check the status of task
+     * Check the status of a task
      *
      * @access private
      * @param  integer   $task_id   Task id
diff --git a/app/Template/task/close.php b/app/Template/task/close.php
index 79150333e..160d54008 100644
--- a/app/Template/task/close.php
+++ b/app/Template/task/close.php
@@ -4,7 +4,7 @@
 
 <div class="confirm">
     <p class="alert alert-info">
-        <?= t('Do you really want to close this task: "%s"?', $this->e($task['title'])) ?>
+        <?= t('Do you really want to close the task "%s" as well as all subtasks?', $this->e($task['title'])) ?>
     </p>
 
     <div class="form-actions">
diff --git a/tests/units/SubtaskTest.php b/tests/units/SubtaskTest.php
index 791f8089a..2abd81d98 100644
--- a/tests/units/SubtaskTest.php
+++ b/tests/units/SubtaskTest.php
@@ -11,6 +11,28 @@ use Model\User;
 
 class SubTaskTest extends Base
 {
+    public function testCloseAll()
+    {
+        $tc = new TaskCreation($this->container);
+        $s = new Subtask($this->container);
+        $p = new Project($this->container);
+
+        $this->assertEquals(1, $p->create(array('name' => 'test1')));
+        $this->assertEquals(1, $tc->create(array('title' => 'test 1', 'project_id' => 1)));
+
+        $this->assertEquals(1, $s->create(array('title' => 'subtask #1', 'task_id' => 1)));
+        $this->assertEquals(2, $s->create(array('title' => 'subtask #2', 'task_id' => 1)));
+
+        $this->assertTrue($s->closeAll(1));
+
+        $subtasks = $s->getAll(1);
+        $this->assertNotEmpty($subtasks);
+
+        foreach ($subtasks as $subtask) {
+            $this->assertEquals(Subtask::STATUS_DONE, $subtask['status']);
+        }
+    }
+
     public function testMoveUp()
     {
         $tc = new TaskCreation($this->container);
diff --git a/tests/units/TaskStatusTest.php b/tests/units/TaskStatusTest.php
index 5c59698b6..c1f79142a 100644
--- a/tests/units/TaskStatusTest.php
+++ b/tests/units/TaskStatusTest.php
@@ -2,6 +2,7 @@
 
 require_once __DIR__.'/Base.php';
 
+use Model\Subtask;
 use Model\Task;
 use Model\TaskCreation;
 use Model\TaskFinder;
@@ -74,4 +75,27 @@ class TaskStatusTest extends Base
         $this->assertArrayHasKey('task_id', $event);
         $this->assertNotEmpty($event['task_id']);
     }
+
+    public function testThatAllSubtasksAreClosed()
+    {
+        $ts = new TaskStatus($this->container);
+        $tc = new TaskCreation($this->container);
+        $s = new Subtask($this->container);
+        $p = new Project($this->container);
+
+        $this->assertEquals(1, $p->create(array('name' => 'test1')));
+        $this->assertEquals(1, $tc->create(array('title' => 'test 1', 'project_id' => 1)));
+
+        $this->assertEquals(1, $s->create(array('title' => 'subtask #1', 'task_id' => 1)));
+        $this->assertEquals(2, $s->create(array('title' => 'subtask #2', 'task_id' => 1)));
+
+        $this->assertTrue($ts->close(1));
+
+        $subtasks = $s->getAll(1);
+        $this->assertNotEmpty($subtasks);
+
+        foreach ($subtasks as $subtask) {
+            $this->assertEquals(Subtask::STATUS_DONE, $subtask['status']);
+        }
+    }
 }