1 files changed, 1 insertions, 3 deletions
diff --git a/packages/0x.js/src/types.ts b/packages/0x.js/src/types.ts
index 04dfe3b0d..91e3c0f20 100644
--- a/packages/0x.js/src/types.ts
+++ b/packages/0x.js/src/types.ts
@@ -501,9 +501,7 @@ export interface OrderStateInvalid {
 
 export type OrderState = OrderStateValid|OrderStateInvalid;
 
-export type OnOrderStateChangeCallbackSync = (orderState: OrderState) => void;
-export type OnOrderStateChangeCallbackAsync = (orderState: OrderState) => Promise<void>;
-export type OnOrderStateChangeCallback = OnOrderStateChangeCallbackAsync|OnOrderStateChangeCallbackSync;
+export type OnOrderStateChangeCallback = (orderState: OrderState) => void;
 
 export interface TransactionReceipt {
     blockHash: string;