diff --git a/contracts/BEBoxMall.sol b/contracts/BEBoxMall.sol
index 0c749eb..8133316 100644
--- a/contracts/BEBoxMall.sol
+++ b/contracts/BEBoxMall.sol
@@ -73,6 +73,7 @@ contract BEBoxMall is Ownable, HasSignature {
             paymentReceivedAddress,
             price
         );
+        usedSignatures[signature] = true;
         // Emit payment event
         emit BEBoxPaid(boxId, userAddress, _type, price, paymentErc20);
     }