diff --git a/src/util.ts b/src/util.ts
index 6e47273..07ddeaf 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -3,7 +3,7 @@ import { createHash } from "node:crypto";
 export const hashDigest = (payload: string | Buffer) =>
     "sha-256="
     + createHash("sha256")
-        .update((Buffer.isBuffer(payload) ? payload : Buffer.from(payload)).toString("hex"))
+        .update(payload)
         .digest("base64");
 
 export const streamToString = async (stream: ReadableStream<Uint8Array>) => {