diff --git a/cors.js b/api/cors.js
similarity index 100%
rename from cors.js
rename to api/cors.js
diff --git a/api/notFound.js b/api/notFound.js
new file mode 100644
index 0000000..84bdd0e
--- /dev/null
+++ b/api/notFound.js
@@ -0,0 +1,5 @@
+const createError = require('http-errors')
+
+module.exports = async (ctx, next) => {
+  throw createError(404)
+}
diff --git a/index.js b/index.js
index 58ae477..211330f 100644
--- a/index.js
+++ b/index.js
@@ -6,9 +6,10 @@ const { middlewareCompose } = require('./libs/helper')
 const functions = require('@google-cloud/functions-framework')
 
 const handlers = middlewareCompose([
-  require('./cors'),
+  require('./api/cors'),
   require('./api/index'),
   require('./line/handler/index'),
+  require('./api/notFound'),
 ])
 
 functions.http('main', async (req, res) => {
diff --git a/line/handler/index.js b/line/handler/index.js
index 42fd504..817f2d4 100644
--- a/line/handler/index.js
+++ b/line/handler/index.js
@@ -13,6 +13,7 @@ const lineEventHander = middlewareCompose([
 
 module.exports = async (ctx, next) => {
   const { req, res } = ctx
+  if (req.method !== 'POST' || _.isNil(req.get('x-line-signature'))) return await next()
   try {
     // 處理 access token
     const channelAccessToken = req.path.substring(1)