diff --git a/index.js b/index.js
index bb34458..65ce943 100644
--- a/index.js
+++ b/index.js
@@ -199,6 +199,9 @@ async function serveResult(request) {
   let dc = new URL(request.url).searchParams.get('decode')
   let code = 200
   let result = await callAPI(request)
+  if (result.includes(`"undef`)){
+    result = `{"success":false,"message":"Cannot find nickname from your request."}`
+  }
   if (JSON.parse(result).success == false) {
     code = 400
   }