diff --git a/client.ts b/client.ts
index e312250..0ece11d 100644
--- a/client.ts
+++ b/client.ts
@@ -67,9 +67,10 @@ app.get("/callback/:cbid", async (req, res) => {
     return;
   }
   const { oidConfig, pkceCodeVerifier, url: redirect_uri } = database[cbid]!;
-  const url = new URL(redirect_uri + req.query);
+  const query = (typeof req.query == "object") ? req.query as Record<string, string> : {};
+  const url = new URL(redirect_uri + `?${new URLSearchParams(query).toString()}`);
   console.log("URL")
-  console.log(redirect_uri + req.query);
+  console.log(url.toString());
   let tokens = await oid
     .authorizationCodeGrant(oidConfig, url, {
       pkceCodeVerifier,