3 files changed, 36 insertions, 2 deletions
diff --git a/src/contract_wrappers/exchange_wrapper.ts b/src/contract_wrappers/exchange_wrapper.ts
index 4698089eb..0b191ed93 100644
--- a/src/contract_wrappers/exchange_wrapper.ts
+++ b/src/contract_wrappers/exchange_wrapper.ts
@@ -22,6 +22,7 @@ import {
     ContractResponse,
     OrderCancellationRequest,
     OrderFillRequest,
+    LogErrorArgs,
 } from '../types';
 import {assert} from '../utils/assert';
 import {utils} from '../utils/utils';
@@ -712,7 +713,7 @@ export class ExchangeWrapper extends ContractWrapper {
     private _throwErrorLogsAsErrors(logs: ContractEvent[]): void {
         const errEvent = _.find(logs, {event: 'LogError'});
         if (!_.isUndefined(errEvent)) {
-            const errCode = errEvent.args.errorId.toNumber();
+            const errCode = (errEvent.args as LogErrorArgs).errorId.toNumber()
             const errMessage = this._exchangeContractErrCodesToMsg[errCode];
             throw new Error(errMessage);
         }
diff --git a/src/index.ts b/src/index.ts
index 7b1a16125..f9037124d 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -19,5 +19,9 @@ export {
     OrderCancellationRequest,
     OrderFillRequest,
     ContractEventEmitter,
+    LogErrorArgs,
+    LogCancelArgs,
+    LogFillArgs,
+    EventArgs,
     Web3Provider,
 } from './types';
diff --git a/src/types.ts b/src/types.ts
index 5be64da53..f15e05d1a 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -191,9 +191,38 @@ export interface ContractEvent {
     address: string;
     type: string;
     event: string;
-    args: any;
+    args: EventArgs;
 }
 
+export interface LogFillArgs {
+    maker: string;
+    taker: string;
+    feeRecipient: string;
+    tokenM: string;
+    tokenT: string;
+    filledValueM: BigNumber.BigNumber;
+    filledValueT: BigNumber.BigNumber;
+    feeMPaid: BigNumber.BigNumber;
+    feeTPaid: BigNumber.BigNumber;
+    tokens: string;
+    orderHash: string;
+}
+export interface LogCancelArgs {
+    maker: string;
+    feeRecipient: string;
+    tokenM: string;
+    tokenT: string;
+    cancelledValueM: BigNumber.BigNumber;
+    cancelledValueT: BigNumber.BigNumber;
+    tokens: string;
+    orderHash: string;
+}
+export interface LogErrorArgs {
+    errorId: BigNumber.BigNumber;
+    orderHash: string;
+}
+export type EventArgs = LogFillArgs|LogCancelArgs|LogErrorArgs;
+
 export interface Order {
     maker: string;
     taker: string;