diff --git a/src/services/missionInventoryUpdateService.ts b/src/services/missionInventoryUpdateService.ts
index 1d985a1e..f4e0e323 100644
--- a/src/services/missionInventoryUpdateService.ts
+++ b/src/services/missionInventoryUpdateService.ts
@@ -709,7 +709,7 @@ export const addMissionRewards = async (
         const conquestType = rewardInfo.ConquestType;
         const conquestNode =
             conquestType == "HexConquest" ? "EchoesHexConquestHardModeUnlocked" : "EntratiLabConquestHardModeUnlocked";
-        if (score >= 25 && inventory.NodeIntrosCompleted.find(x => x == conquestNode) === undefined)
+        if (score >= 25 && inventory.NodeIntrosCompleted.indexOf(conquestNode) == -1)
             inventory.NodeIntrosCompleted.push(conquestNode);
 
         if (conquestType == "HexConquest") {