diff --git a/contracts/mysterybox/MysteryBoxProxy.sol b/contracts/mysterybox/MysteryBoxProxy.sol
index 1a784d2..4a4cbb4 100644
--- a/contracts/mysterybox/MysteryBoxProxy.sol
+++ b/contracts/mysterybox/MysteryBoxProxy.sol
@@ -69,7 +69,7 @@ contract MysteryBoxProxy is Ownable, Initializable, HasSignature {
 
     function openBox(
         uint256 boxId,
-        uint256[3] memory ids,
+        uint256[3] calldata ids,
         uint256 saltNonce,
         bytes calldata signature
     ) external {