diff --git a/src/common/cancel-task.ts b/src/common/cancel-task.ts
index 315a151f1..9d3de6527 100644
--- a/src/common/cancel-task.ts
+++ b/src/common/cancel-task.ts
@@ -1,4 +1,4 @@
-type TaskExecutor<T> = (resolve: (value: T | PromiseLike<T>) => void, reject: (reason?: any) => void, onCancel: (callback: () => void) => void) => void;
+export type TaskExecutor<T> = (resolve: (value: T | PromiseLike<T>) => void, reject: (reason?: any) => void, onCancel: (callback: () => void) => void) => void;
 
 export class CancelableTask<T> {
     private promise: Promise<T>;