diff --git a/pkg/models/tasks.go b/pkg/models/tasks.go
index 69ce2eb99..4f9e45f1a 100644
--- a/pkg/models/tasks.go
+++ b/pkg/models/tasks.go
@@ -929,6 +929,22 @@ func (t *Task) Update(s *xorm.Session, a web.Auth) (err error) {
 
 	// Make sure we have a bucket
 	var bucket *Bucket
+	if t.Done {
+		bucket = &Bucket{}
+		exists, err := s.
+			Where("list_id = ? and is_done_bucket = ?", t.ListID, true).
+			Get(bucket)
+		if err != nil {
+			return err
+		}
+		if !exists {
+			bucket = nil
+		}
+		if bucket != nil {
+			t.BucketID = bucket.ID
+		}
+	}
+
 	if t.BucketID == 0 || (t.ListID != 0 && ot.ListID != t.ListID) {
 		bucket, err = getDefaultBucket(s, t.ListID)
 		if err != nil {
diff --git a/pkg/models/tasks_test.go b/pkg/models/tasks_test.go
index 20af79e7d..67a5db283 100644
--- a/pkg/models/tasks_test.go
+++ b/pkg/models/tasks_test.go
@@ -260,6 +260,28 @@ func TestTask_Update(t *testing.T) {
 		assert.Equal(t, int64(4), task.BucketID) // bucket 4 is the default bucket on list 2
 		assert.True(t, task.Done)                // bucket 4 is the done bucket, so the task should be marked as done as well
 	})
+	t.Run("marking a task as done should move it to the done bucket", func(t *testing.T) {
+		db.LoadAndAssertFixtures(t)
+		s := db.NewSession()
+		defer s.Close()
+
+		task := &Task{
+			ID:   1,
+			Done: true,
+		}
+		err := task.Update(s, u)
+		assert.NoError(t, err)
+		err = s.Commit()
+		assert.NoError(t, err)
+		assert.True(t, task.Done)
+		assert.Equal(t, int64(3), task.BucketID)
+
+		db.AssertExists(t, "tasks", map[string]interface{}{
+			"id":        1,
+			"done":      true,
+			"bucket_id": 3,
+		}, false)
+	})
 }
 
 func TestTask_Delete(t *testing.T) {