diff --git a/SVSim.EmulatedEntrypoint/Services/BattlePassService.cs b/SVSim.EmulatedEntrypoint/Services/BattlePassService.cs
index db097cd..0707e94 100644
--- a/SVSim.EmulatedEntrypoint/Services/BattlePassService.cs
+++ b/SVSim.EmulatedEntrypoint/Services/BattlePassService.cs
@@ -198,12 +198,12 @@ public sealed class BattlePassService : IBattlePassService
         await _db.SaveChangesAsync(ct);
         await tx.CommitAsync(ct);
 
-        // Post-state reward_list must also include the crystal balance after the deduction.
-        if (!postState.Any(r => r.RewardType == (int)UserGoodsType.Crystal))
-        {
-            postState.Add(new GrantedReward(
-                (int)UserGoodsType.Crystal, 0, checked((int)viewer.Currency.Crystals)));
-        }
+        // Post-state reward_list must always include the crystal balance after the deduction.
+        // Unconditionally overwrite: remove any crystal entry ApplyAsync may have added, then
+        // append the post-deduction total so the client gets the correct final balance.
+        postState.RemoveAll(r => r.RewardType == (int)UserGoodsType.Crystal);
+        postState.Add(new GrantedReward(
+            (int)UserGoodsType.Crystal, 0, checked((int)viewer.Currency.Crystals)));
 
         return new BattlePassBuyOutcome(1, achieved, postState);
     }