diff --git a/packages/contracts/test/utils/exchange_wrapper.ts b/packages/contracts/test/utils/exchange_wrapper.ts
index 52322d5c41..c28989d3f6 100644
--- a/packages/contracts/test/utils/exchange_wrapper.ts
+++ b/packages/contracts/test/utils/exchange_wrapper.ts
@@ -212,7 +212,7 @@ export class ExchangeWrapper {
         return tx;
     }
     public async getTakerAssetFilledAmountAsync(orderHashHex: string): Promise<BigNumber> {
-        const filledAmount = new BigNumber(await this._exchange.filled.callAsync(orderHashHex));
+        const filledAmount = await this._exchange.filled.callAsync(orderHashHex);
         return filledAmount;
     }
     public async isCancelledAsync(orderHashHex: string): Promise<boolean> {
@@ -220,7 +220,7 @@ export class ExchangeWrapper {
         return isCancelled;
     }
     public async getOrderEpochAsync(makerAddress: string, senderAddress: string): Promise<BigNumber> {
-        const orderEpoch = new BigNumber(await this._exchange.orderEpoch.callAsync(makerAddress, senderAddress));
+        const orderEpoch = await this._exchange.orderEpoch.callAsync(makerAddress, senderAddress);
         return orderEpoch;
     }
     public async getOrderInfoAsync(signedOrder: SignedOrder): Promise<OrderInfo> {