diff --git a/webapp/controller/MissionController.class.php b/webapp/controller/MissionController.class.php
index cc65f07..fb7642a 100644
--- a/webapp/controller/MissionController.class.php
+++ b/webapp/controller/MissionController.class.php
@@ -135,7 +135,8 @@ class MissionController extends BaseAuthedController {
             $missionMeta = mt\Mission::get($missionDto['mission_id']);
             $dropMeta = mt\Drop::get($missionMeta['reward']);
             if ($dropMeta) {
-                $this->_scatterDrop($dropMeta, $this->awardService, $this->propertyChgService);
+                $dropSource = 'mission:' . $missionDto['mission_id'];
+                $this->_scatterDrop($dropSource, $dropMeta, $this->awardService, $this->propertyChgService);
             }
         }
         $this->_rspData(array(