diff --git a/src/oidc.js b/src/oidc.js
index 40d38acb2..3fc2d9638 100644
--- a/src/oidc.js
+++ b/src/oidc.js
@@ -831,7 +831,7 @@ async function start() {
         },
         clientDefaults: {
             response_types: ['code', 'id_token'],
-            grant_types: ['authorization_code', 'implicit']
+            grant_types: ['authorization_code', 'implicit', 'refresh_token']
         },
         responseTypes: [
             'code',