1 files changed, 1 insertions, 1 deletions
diff --git a/src/contract_wrappers/exchange_wrapper.ts b/src/contract_wrappers/exchange_wrapper.ts
index 8ae51da43..d09df236b 100644
--- a/src/contract_wrappers/exchange_wrapper.ts
+++ b/src/contract_wrappers/exchange_wrapper.ts
@@ -73,7 +73,7 @@ export class ExchangeWrapper extends ContractWrapper {
         ];
         return [orderAddresses, orderValues];
     }
-    constructor(web3Wrapper: Web3Wrapper, tokenWrapper: TokenWrapper, gasPrice: BigNumber.BigNumber) {
+    constructor(web3Wrapper: Web3Wrapper, tokenWrapper: TokenWrapper, gasPrice?: BigNumber.BigNumber) {
         super(web3Wrapper, gasPrice);
         this._tokenWrapper = tokenWrapper;
         this._orderValidationUtils = new OrderValidationUtils(tokenWrapper, this);