diff --git a/scripts/bg.js b/scripts/bg.js
index 150801b3..105d66c6 100644
--- a/scripts/bg.js
+++ b/scripts/bg.js
@@ -796,6 +796,8 @@ function downloadURL(urls, cb) {
 			downloadURL();
 		},
 		beforeSend: function(xhr) {
+			xhr.setRequestHeader('Cache-Control', 'no-cache');
+			xhr.setRequestHeader('Pragma', 'no-cache');
 			xhr.setRequestHeader('If-Modified-Since', 'Tue, 1 Jan 1991 00:00:00 GMT');
 			xhr.setRequestHeader('X-Time-Stamp', Date.now());
 		}