diff --git a/gulp-shell/gulp-shell.d.ts b/gulp-shell/gulp-shell.d.ts
index d88f27ed6a..4d18d610c8 100644
--- a/gulp-shell/gulp-shell.d.ts
+++ b/gulp-shell/gulp-shell.d.ts
@@ -10,7 +10,7 @@ declare module "gulp-shell" {
     namespace shell {
         interface Shell {
             (commands: string|string[], options?: Option): NodeJS.ReadWriteStream;
-            task(commands: string|string[], options?: Option): () => NodeJS.ReadWriteStream;
+            task(commands: string|string[], options?: Option): (done: Function) => NodeJS.ReadWriteStream;
         }
 
         interface Option {