diff --git a/routes/get.js b/routes/get.js
index 82429d9..c08adba 100644
--- a/routes/get.js
+++ b/routes/get.js
@@ -1,10 +1,10 @@
 function htmlEncode (str) {
-    return str.replace(/&/g, '&')
+    return str ? str.replace(/&/g, '&')
         .replace(/</g, '&lt;')
         .replace(/>/g, '&gt;')
         .replace(/"/g, '&quot;')
         .replace(/'/g, '&#x27;')
-        .replace(/\//g, '&#x2f;');
+        .replace(/\//g, '&#x2f;') : '';
 }
 
 module.exports = async (ctx) => {