diff --git a/index.d.ts b/index.d.ts
index 827d0b7..1ca6ece 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1,7 +1,9 @@
-export function onShutdown(
-    name: (() => Promise<void>) | string | string[],
-    dependencies?: (() => Promise<void>) | string[],
-    handler?: () => Promise<void>
-): void;
+interface OnShutdown {
+  (handler: ()=> Promise<void>): void
+  (name: string, handler: ()=> Promise<void>): void
+  (name: string, dependencies: string[], handler: ()=> Promise<void>): void
+}
+
+export const onShutdown: OnShutdown
 
 export function onShutdownError(callback: (error: Error) => Promise<void>): void;