1 files changed, 4 insertions, 1 deletions
diff --git a/src/contract_wrappers/exchange_wrapper.ts b/src/contract_wrappers/exchange_wrapper.ts
index f0f6e79f7..0c7f27507 100644
--- a/src/contract_wrappers/exchange_wrapper.ts
+++ b/src/contract_wrappers/exchange_wrapper.ts
@@ -78,7 +78,7 @@ export class ExchangeWrapper extends ContractWrapper {
 
         const senderAddress = await this.web3Wrapper.getSenderAddressOrThrowAsync();
         const exchangeInstance = await this.getExchangeContractAsync();
-        const zrxTokenAddress = await exchangeInstance.ZRX.call();
+        const zrxTokenAddress = await this.getZRXTokenAddressAsync(exchangeInstance);
         await this.validateFillOrderAsync(signedOrder, fillTakerAmount, senderAddress, zrxTokenAddress);
 
         const orderAddresses: OrderAddresses = [
@@ -226,4 +226,7 @@ export class ExchangeWrapper extends ContractWrapper {
         this.exchangeContractIfExists = contractInstance as ExchangeContract;
         return this.exchangeContractIfExists;
     }
+    private async getZRXTokenAddressAsync(exchangeInstance: ExchangeContract): Promise<string> {
+        return exchangeInstance.ZRX.call();
+    }
 }