diff --git a/webapp/services/BattleBoxService.php b/webapp/services/BattleBoxService.php
index 0803d769..1608ee0f 100644
--- a/webapp/services/BattleBoxService.php
+++ b/webapp/services/BattleBoxService.php
@@ -97,6 +97,7 @@ class BattleBoxService {
                     $completionDegree = $yesterDayDropTotal / $yesterDayAllocNum;
                 }
                 $allocableNum = min($maxNumLimit, $yesterDayAllocNum * $completionDegree);
+                $allocableNum = max(300, $allocableNum);
                 if ($allocableNum <= 0) {
                     $allocableNum = $yesterDayAllocNum;
                 }