diff --git a/async/async.d.ts b/async/async.d.ts
index 543b3751d..b266786b6 100644
--- a/async/async.d.ts
+++ b/async/async.d.ts
@@ -127,8 +127,8 @@ interface Async {
     doDuring(fn: AsyncVoidFunction, test: (testCallback: (error: Error, truth: boolean) => void) => void, callback: (err: any) => void): void;
     forever(next: (errCallback : (err: Error) => void) => void, errBack: (err: Error) => void) : void;
     waterfall(tasks: Function[], callback?: (err: Error, results?: any) => void): void;
-    compose(...fns: Function[]): void;
-    seq(...fns: Function[]): void;
+    compose(...fns: Function[]): Function;
+    seq(...fns: Function[]): Function;
     applyEach(fns: Function[], argsAndCallback: any[]): void;           // applyEach(fns, args..., callback). TS does not support ... for a middle argument. Callback is optional.
     applyEachSeries(fns: Function[], argsAndCallback: any[]): void;     // applyEachSeries(fns, args..., callback). TS does not support ... for a middle argument. Callback is optional.
     queue<T>(worker: AsyncWorker<T>, concurrency?: number): AsyncQueue<T>;