1 files changed, 3 insertions, 3 deletions
diff --git a/packages/contracts/test/utils/exchange_wrapper.ts b/packages/contracts/test/utils/exchange_wrapper.ts
index a71a0d495..490ea959b 100644
--- a/packages/contracts/test/utils/exchange_wrapper.ts
+++ b/packages/contracts/test/utils/exchange_wrapper.ts
@@ -11,9 +11,9 @@ import { orderUtils } from './order_utils';
 import { OrderInfo, SignedTransaction } from './types';
 
 export class ExchangeWrapper {
-    private _exchange: ExchangeContract;
-    private _web3Wrapper: Web3Wrapper;
-    private _logDecoder: LogDecoder;
+    private readonly _exchange: ExchangeContract;
+    private readonly _web3Wrapper: Web3Wrapper;
+    private readonly _logDecoder: LogDecoder;
     constructor(exchangeContract: ExchangeContract, provider: Provider) {
         this._exchange = exchangeContract;
         this._web3Wrapper = new Web3Wrapper(provider);