diff --git a/webapp/services/MissionService.php b/webapp/services/MissionService.php
index 5fdbb38c..d4a7d7af 100644
--- a/webapp/services/MissionService.php
+++ b/webapp/services/MissionService.php
@@ -592,8 +592,8 @@ class MissionService extends BaseService {
         $metas = mt\Task::getOfferRewardMissions
                ($this->offerRewartdMission['missions']);
         $selectMeta = null;
-        foreach (array_rand($metas, count($metas)) as $key) {
-            $meta = $metas[$key];
+        shuffle($metas);
+        foreach ($metas as $meta) {
             if (!$this->inOfferRewardMission($meta['id'])) {
                 $selectMeta = $meta;
                 break;