diff --git a/index.d.ts b/index.d.ts
index f8f89c567f394a538018bfdf11c28dc15e9c9fdc..f3d1cd426711f1f714744474604bd7e321073983 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1,4 +1,4 @@
 /// <reference types="node"/>
 
-export function decode(str: string | Buffer): string;
+export function decode(str: string | Buffer): Buffer;
 export function encode(str: string | Buffer): string;