diff --git a/frontend/src/fileReceiver.js b/frontend/src/fileReceiver.js
index 79e25f67..db1d60c1 100644
--- a/frontend/src/fileReceiver.js
+++ b/frontend/src/fileReceiver.js
@@ -21,7 +21,7 @@ class FileReceiver extends EventEmitter {
           }
         };
 
-        xhr.onload = event => {
+        xhr.onload = function(event) {
           if (xhr.status === 404) {
             reject(
               new Error('The file has expired, or has already been deleted.')