diff --git a/webapp/services/BattleBoxService.php b/webapp/services/BattleBoxService.php
index 3eebbce2..8fe31003 100644
--- a/webapp/services/BattleBoxService.php
+++ b/webapp/services/BattleBoxService.php
@@ -96,6 +96,9 @@ class BattleBoxService {
                     $completionDegree = $yesterDayDropTotal / $yesterDayAllocNum;
                 }
                 $allocableNum = min($maxNumLimit, $yesterDayAllocNum * $completionDegree);
+                if ($allocableNum <= 0) {
+                    $allocableNum = $yesterDayAllocNum;
+                }
             }
             if ($allocableNum > 0) {
                 self::setDailyPhaseAllocNum($currPhase, myself()->_getNowDaySeconds(), $allocableNum);