diff --git a/packages/checkout/sdk/src/smartCheckout/sell/sell.ts b/packages/checkout/sdk/src/smartCheckout/sell/sell.ts
index c06a92a439..ad60075714 100644
--- a/packages/checkout/sdk/src/smartCheckout/sell/sell.ts
+++ b/packages/checkout/sdk/src/smartCheckout/sell/sell.ts
@@ -253,10 +253,7 @@ export const sell = async (
       let tokenQuantity = BigNumber.from(1);
 
       // if type exists in sellToken then it is valid ERC721 or ERC1155 and not deprecated type
-      if ('type' in sellToken) {
-        const erc1155Token = sellToken as unknown as ERC1155Item | ERC721Item;
-        if (erc1155Token.type === ItemType.ERC1155) tokenQuantity = BigNumber.from(erc1155Token.amount);
-      }
+      if (sellTokenHasType && sellToken.type === ItemType.ERC1155) tokenQuantity = BigNumber.from(sellToken.amount);
 
       const orderBookFees = calculateFees(makerFees, buyTokenOrNative.amount, decimals, tokenQuantity);
       if (orderBookFees.length !== makerFees.length) {