2 files changed, 10 insertions, 8 deletions
diff --git a/packages/0x.js/src/order_watcher/expiration_watcher.ts b/packages/0x.js/src/order_watcher/expiration_watcher.ts
index 7d6ce6bdd..efedd3cf8 100644
--- a/packages/0x.js/src/order_watcher/expiration_watcher.ts
+++ b/packages/0x.js/src/order_watcher/expiration_watcher.ts
@@ -29,12 +29,12 @@ export class ExpirationWatcher {
         const comparator = (lhs: string, rhs: string) => scoreFunction(lhs) - scoreFunction(rhs);
         this.orderHashByExpirationRBTree = new RBTree(comparator);
     }
-    public subscribe(callback: (orderHash: string) => void): void {
+    public subscribe(callbackAsync: (orderHash: string) => Promise<void>): void {
         if (!_.isUndefined(this.orderExpirationCheckingIntervalIdIfExists)) {
             throw new Error(ZeroExError.SubscriptionAlreadyPresent);
         }
         this.orderExpirationCheckingIntervalIdIfExists = intervalUtils.setAsyncExcludingInterval(
-            this.pruneExpiredOrders.bind(this, callback), this.orderExpirationCheckingIntervalMs,
+            this.pruneExpiredOrdersAsync.bind(this, callbackAsync), this.orderExpirationCheckingIntervalMs,
         );
     }
     public unsubscribe(): void {
@@ -52,7 +52,7 @@ export class ExpirationWatcher {
         this.orderHashByExpirationRBTree.remove(orderHash);
         delete this.expiration[orderHash];
     }
-    private pruneExpiredOrders(callback: (orderHash: string) => void): void {
+    private async pruneExpiredOrdersAsync(callbackAsync: (orderHash: string) => Promise<void>): Promise<void> {
         const currentUnixTimestampMs = utils.getCurrentUnixTimestampMs();
         while (
             this.orderHashByExpirationRBTree.size !== 0 &&
@@ -63,7 +63,7 @@ export class ExpirationWatcher {
             const orderHash = this.orderHashByExpirationRBTree.min();
             this.orderHashByExpirationRBTree.remove(orderHash);
             delete this.expiration[orderHash];
-            callback(orderHash);
+            await callbackAsync(orderHash);
         }
     }
 }
diff --git a/packages/0x.js/src/order_watcher/order_state_watcher.ts b/packages/0x.js/src/order_watcher/order_state_watcher.ts
index 579fa388a..84f2128c0 100644
--- a/packages/0x.js/src/order_watcher/order_state_watcher.ts
+++ b/packages/0x.js/src/order_watcher/order_state_watcher.ts
@@ -128,7 +128,7 @@ export class OrderStateWatcher {
         }
         this._callbackIfExists = callback;
         this._eventWatcher.subscribe(this._onEventWatcherCallbackAsync.bind(this));
-        this._expirationWatcher.subscribe(this._onOrderExpired.bind(this));
+        this._expirationWatcher.subscribe(this._onOrderExpiredAsync.bind(this));
     }
     /**
      * Ends an orderStateWatcher subscription.
@@ -143,7 +143,7 @@ export class OrderStateWatcher {
         this._eventWatcher.unsubscribe();
         this._expirationWatcher.unsubscribe();
     }
-    private _onOrderExpired(orderHash: string): void {
+    private async _onOrderExpiredAsync(orderHash: string): Promise<void> {
         const orderState: OrderState = {
             isValid: false,
             orderHash,
@@ -151,8 +151,10 @@ export class OrderStateWatcher {
         };
         if (!_.isUndefined(this._orderByOrderHash[orderHash])) {
             // We need this check because we never remove the orders from expiration watcher
-            this.removeOrder(orderHash);
-            (this._callbackIfExistsAsync as OnOrderStateChangeCallback)(orderState);
+            await this.removeOrderAsync(orderHash);
+            if (!_.isUndefined(this._callbackIfExists)) {
+                this._callbackIfExists(orderState);
+            }
         }
     }
     private async _onEventWatcherCallbackAsync(log: LogEvent): Promise<void> {