diff --git a/lib/web/imageRouter/s3.js b/lib/web/imageRouter/s3.js
index 5bbd647f..7fd78c32 100644
--- a/lib/web/imageRouter/s3.js
+++ b/lib/web/imageRouter/s3.js
@@ -26,7 +26,7 @@ exports.uploadImage = function (imagePath, callback) {
       callback(new Error(err), null)
       return
     }
-    let params = {
+    const params = {
       Bucket: config.s3bucket,
       Key: path.join('uploads', path.basename(imagePath)),
       Body: buffer