diff --git a/src/Collins/Sign/JWS/SignService.php b/src/Collins/Sign/JWS/SignService.php
index f18e617..9105bb3 100644
--- a/src/Collins/Sign/JWS/SignService.php
+++ b/src/Collins/Sign/JWS/SignService.php
@@ -39,7 +39,7 @@ public function getPayload($signedData)
         $jws = Akita_JOSE_JWS::load($signedData, true);
         if(!$jws) throw new \Exception('could not jws get create');
         $json = $jws->getPayload($signedData);
-        if(!$jws) throw new \Exception('could not jws get payload');
+        if(!$json) throw new \Exception('could not jws get payload');
         $payload = json_decode($json);
         if(is_null($payload)) throw new \Exception('could not jws get json decode');
         $okm = $this->createORMToken(base64_decode($payload->salt),$payload->info);
@@ -129,4 +129,4 @@ private function hkdf($hash, $ikm, $length, $info = '', $salt = null)
         return $orm;
     }
 
-}
\ No newline at end of file
+}