diff --git a/composer.json b/composer.json
index a69e9dd0..c84b270c 100644
--- a/composer.json
+++ b/composer.json
@@ -19,7 +19,8 @@
     "psr/container": "^1.0 | ^2.0",
     "psr/http-client-implementation": "^1.0",
     "vonage/nexmo-bridge": "^0.1.0",
-    "psr/log": "^1.1|^2.0|^3.0"
+    "psr/log": "^1.1|^2.0|^3.0",
+    "vonage/jwt": "^0.4.0"
   },
   "require-dev": {  
     "guzzlehttp/guzzle": ">=6",
diff --git a/src/Client/Credentials/Keypair.php b/src/Client/Credentials/Keypair.php
index 893863de..bbf7565b 100644
--- a/src/Client/Credentials/Keypair.php
+++ b/src/Client/Credentials/Keypair.php
@@ -12,11 +12,14 @@
 namespace Vonage\Client\Credentials;
 
 use Lcobucci\JWT\Configuration;
+use Lcobucci\JWT\Encoding\JoseEncoder;
 use Lcobucci\JWT\Signer\Key;
 use Lcobucci\JWT\Signer\Key\InMemory;
 use Lcobucci\JWT\Signer\Rsa\Sha256;
 use Lcobucci\JWT\Token;
 use Vonage\Application\Application;
+use Vonage\Client\Exception\Validation;
+use Vonage\JWT\TokenGenerator;
 
 use function base64_encode;
 use function mt_rand;
@@ -27,14 +30,9 @@
  */
 class Keypair extends AbstractCredentials
 {
-    /**
-     * @var Key
-     */
-    protected $key;
-
-    public function __construct($privateKey, $application = null)
+    public function __construct(protected string $key, $application = null)
     {
-        $this->credentials['key'] = $privateKey;
+        $this->credentials['key'] = $key;
 
         if ($application) {
             if ($application instanceof Application) {
@@ -43,71 +41,62 @@ public function __construct($privateKey, $application = null)
 
             $this->credentials['application'] = $application;
         }
-
-        $this->key = InMemory::plainText($privateKey);
     }
 
     /**
-     * @return Key
+     * @deprecated Old public signature using Lcobucci/Jwt directly
      */
     public function getKey(): Key
+    {
+        return InMemory::plainText($this->key);
+    }
+
+    public function getKeyRaw(): string
     {
         return $this->key;
     }
 
     public function generateJwt(array $claims = []): Token
     {
-        $config = Configuration::forSymmetricSigner(new Sha256(), $this->key);
-
-        $exp = time() + 60;
-        $iat = time();
-        $jti = base64_encode((string)mt_rand());
+        $generator = new TokenGenerator($this->application, $this->getKeyRaw());
 
         if (isset($claims['exp'])) {
-            $exp = $claims['exp'];
-
+            trigger_error('Expiry date is automatically generated from now and TTL, so cannot be passed in
+            as an argument in claims', E_USER_WARNING);
             unset($claims['exp']);
         }
 
-        if (isset($claims['iat'])) {
-            $iat = $claims['iat'];
-
-            unset($claims['iat']);
+        if (isset($claims['ttl'])) {
+            $generator->setTTL($claims['ttl']);
+            unset($claims['ttl']);
         }
 
         if (isset($claims['jti'])) {
-            $jti = $claims['jti'];
-
+            $generator->setJTI($claims['jti']);
             unset($claims['jti']);
         }
 
-        $builder = $config->builder();
-        $builder->issuedAt((new \DateTimeImmutable())->setTimestamp($iat))
-            ->expiresAt((new \DateTimeImmutable())->setTimestamp($exp))
-            ->identifiedBy($jti);
-
         if (isset($claims['nbf'])) {
-            $builder->canOnlyBeUsedAfter((new \DateTimeImmutable())->setTimestamp($claims['nbf']));
-
-            unset($claims['nbf']);
-        }
-
-        if (isset($this->credentials['application'])) {
-            $builder->withClaim('application_id', $this->credentials['application']);
+            // Due to older versions of lcobucci/jwt, this claim has
+            // historic fraction conversation issues. For now, nbf is not supported.
+            throw new Validation('NotBefore Claim is not supported in Vonage JWT');
         }
 
         if (isset($claims['sub'])) {
-            $builder->relatedTo($claims['sub']);
-
+            $generator->setSubject($claims['sub']);
             unset($claims['sub']);
         }
 
         if (!empty($claims)) {
             foreach ($claims as $claim => $value) {
-                $builder->withClaim($claim, $value);
+                $generator->addClaim($claim, $value);
             }
         }
 
-        return $builder->getToken($config->signer(), $config->signingKey());
+        $jwt = $generator->generate();
+        $parser = new Token\Parser(new JoseEncoder());
+
+        // Backwards compatible for signature. In 5.0 this will return a string value
+        return $parser->parse($jwt);
     }
 }
diff --git a/test/Client/Credentials/KeypairTest.php b/test/Client/Credentials/KeypairTest.php
index 8c7ab356..78fbd5a5 100644
--- a/test/Client/Credentials/KeypairTest.php
+++ b/test/Client/Credentials/KeypairTest.php
@@ -71,8 +71,7 @@ public function testAdditionalClaims(): void
                 'nested' => [
                     'data' => "something"
                 ]
-            ],
-            'nbf' => 900
+            ]
         ];
 
         $jwt = $credentials->generateJwt($claims);
@@ -80,18 +79,15 @@ public function testAdditionalClaims(): void
 
         $this->assertArrayHasKey('arbitrary', $payload);
         $this->assertEquals($claims['arbitrary'], $payload['arbitrary']);
-        $this->assertArrayHasKey('nbf', $payload);
-        $this->assertEquals(900, $payload['nbf']);
     }
 
     /**
      * @link https://github.com/Vonage/vonage-php-sdk-core/issues/276
      */
-    public function testExampleConversationJWTWorks()
+    public function testExampleConversationJWTWorks(): void
     {
         $credentials = new Keypair($this->key, $this->application);
         $claims = [
-            'exp' => strtotime(date('Y-m-d', strtotime('+24 Hours'))),
             'sub' => 'apg-cs',
             'acl' => [
                 'paths' => [
@@ -113,7 +109,6 @@ public function testExampleConversationJWTWorks()
         [, $payload] = $this->decodeJWT($jwt->toString());
 
         $this->assertArrayHasKey('exp', $payload);
-        $this->assertEquals($claims['exp'], $payload['exp']);
         $this->assertEquals($claims['sub'], $payload['sub']);
     }