diff --git a/package.json b/package.json
index 76f793d..4dd8ac1 100644
--- a/package.json
+++ b/package.json
@@ -60,7 +60,7 @@
     "typescript": "^4.9.4"
   },
   "dependencies": {
-    "jose": "^4.11.2",
+    "@tsndr/cloudflare-worker-jwt": "^2.5.2",
     "superstruct": "^1.0.3"
   }
 }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 2ddf954..b14b875 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -5,9 +5,9 @@ settings:
   excludeLinksFromLockfile: false
 
 dependencies:
-  jose:
-    specifier: ^4.11.2
-    version: 4.11.2
+  '@tsndr/cloudflare-worker-jwt':
+    specifier: ^2.5.2
+    version: 2.5.3
   superstruct:
     specifier: ^1.0.3
     version: 1.0.3
@@ -571,6 +571,10 @@ packages:
       playwright-core: 1.29.2
     dev: true
 
+  /@tsndr/cloudflare-worker-jwt@2.5.3:
+    resolution: {integrity: sha512-zbdvjRG86y/ObiBgTJrzBC39t2FcaeGwB6AV7VO4LvHKJNyZvLYRbKT68eaoJhnJldyHhs7yZ69neRVdUd9knA==}
+    dev: false
+
   /@types/is-ci@3.0.0:
     resolution: {integrity: sha512-Q0Op0hdWbYd1iahB+IFNQcWXFq4O0Q5MwQP7uN0souuQ4rPg1vEYcnIOfr1gY+M+6rc8FGoRaBO1mOOvL29sEQ==}
     dependencies:
@@ -1823,10 +1827,6 @@ packages:
     resolution: {integrity: sha512-RHxMLp9lnKHGHRng9QFhRCMbYAcVpn69smSGcq3f36xjgVVWThj4qqLbTLlq7Ssj8B+fIQ1EuCEGI2lKsyQeIw==}
     dev: true
 
-  /jose@4.11.2:
-    resolution: {integrity: sha512-njj0VL2TsIxCtgzhO+9RRobBvws4oYyCM8TpvoUQwl/MbIM3NFJRR9+e6x0sS5xXaP1t6OCBkaBME98OV9zU5A==}
-    dev: false
-
   /js-sdsl@4.2.0:
     resolution: {integrity: sha512-dyBIzQBDkCqCu+0upx25Y2jGdbTGxE9fshMsCdK0ViOongpV+n5tXRcZY9v7CaVQ79AGS9KA1KHtojxiM7aXSQ==}
     dev: true
diff --git a/src/init.ts b/src/init.ts
index 6703d96..f924730 100644
--- a/src/init.ts
+++ b/src/init.ts
@@ -1,9 +1,9 @@
-import * as jose from 'jose';
+import { sign } from '@tsndr/cloudflare-worker-jwt';
 
 import type * as Firestore from './types';
 import { FIRESTORE_ENDPOINT } from './utils';
 
-const alg = 'RS256';
+const algorithm = 'RS256';
 const aud = `${FIRESTORE_ENDPOINT}/`;
 
 /**
@@ -27,19 +27,20 @@ export const init = async ({
   uid: string;
   claims?: Record<string, string>;
 }): Promise<Firestore.DB> => {
-  const sign_key = await jose.importPKCS8(private_key.replace(/\\n/g, '\n'), alg);
-
-  const jwt = await new jose.SignJWT({
-    aud,
-    uid,
-    claims,
-    sub: client_email,
-    iss: client_email,
-  })
-    .setProtectedHeader({ alg, kid: private_key_id })
-    .setIssuedAt()
-    .setExpirationTime('1h')
-    .sign(sign_key);
+  const jwt = await sign(
+    {
+      aud,
+      uid,
+      claims,
+      sub: client_email,
+      iss: client_email,
+      iat: Math.floor(Date.now() / 1000),
+      exp: Math.floor(Date.now() / 1000) + 3600,
+      ...claims,
+    },
+    private_key,
+    { algorithm, header: { kid: private_key_id } }
+  );
 
   return {
     project_id,