diff --git a/lib/Mangrove-reviews.ts b/lib/Mangrove-reviews.ts
index 921b89e..2e22e80 100644
--- a/lib/Mangrove-reviews.ts
+++ b/lib/Mangrove-reviews.ts
@@ -75,12 +75,12 @@ export class MangroveReviews {
         payload = MangroveReviews.cleanPayload(payload)
         const algo = 'ES256'
         const kid = await MangroveReviews.publicToPem(keypair.publicKey)
-        const jwk = await crypto.subtle.exportKey('jwk', keypair.publicKey)
+        const jwk = JSON.stringify(await crypto.subtle.exportKey('jwk', keypair.publicKey))
         return await new SignJWT(<JWTPayload>payload)
             .setProtectedHeader({
                 alg: algo,
                 kid,
-                jwk,
+                jwk: <any> jwk,
                 enc: "utf-8"
             })
             .sign(keypair.privateKey);
diff --git a/package.json b/package.json
index ebe07da..eacb66e 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "mangrove-reviews-typescript",
-  "version": "0.0.5",
+  "version": "0.0.6",
   "description": "A library to interface with Mangrove.reviews",
   "main": "lib/index.ts",
   "scripts": {