diff --git a/classes/core_jwt_manager.php b/classes/core_jwt_manager.php
index 69247ea..eb6a114 100644
--- a/classes/core_jwt_manager.php
+++ b/classes/core_jwt_manager.php
@@ -79,7 +79,7 @@ class core_jwt_manager
 
         $secret = $this->config->jwtsecret;
 
-        return JWT::encode($payload, $secret);
+        return JWT::encode($payload, $secret, 'HS256');
     }
 
     /**
@@ -96,7 +96,7 @@ class core_jwt_manager
         $secret = $this->config->jwtsecret;
 
         try {
-            $decoded = JWT::decode($keyvalue, $secret, ['HS256']);
+            $decoded = JWT::decode($keyvalue, $secret);
         } catch (\Exception $e) {
             throw new \moodle_exception('invalidkey');
         }