diff --git a/static/js/potd.js b/static/js/potd.js
index 0fd4786..055e917 100644
--- a/static/js/potd.js
+++ b/static/js/potd.js
@@ -3,12 +3,13 @@ function potd_set_background() {
     if (cookie) {
         try {
             data = JSON.parse(cookie);
+            var filename = data.filename;
             var url = data.url;
             var descurl = data.descurl;
             var imgwidth = data.imgwidth;
             var imgheight = data.imgheight;
-            if (url && descurl && imgwidth && imgheight) {
-                set_background(url, descurl, imgwidth, imgheight);
+            if (filename && url && descurl && imgwidth && imgheight) {
+                set_background(filename, url, descurl, imgwidth, imgheight);
                 return;
             }
         }
@@ -72,8 +73,8 @@ function parse_file_url(data, filename) {
         imgheight = r["height"];
     }
 
-    set_background(url, descurl, imgwidth, imgheight);
-    var data = {"url": url, "descurl": descurl, "imgwidth": imgwidth, "imgheight": imgheight};
+    set_background(filename, url, descurl, imgwidth, imgheight);
+    var data = {"filename": filename, "url": url, "descurl": descurl, "imgwidth": imgwidth, "imgheight": imgheight};
     var expires = new Date();
     expires.setUTCMilliseconds(0);
     expires.setUTCSeconds(0);
@@ -83,7 +84,7 @@ function parse_file_url(data, filename) {
     set_cookie_with_date("EarwigBackgroundCache", JSON.stringify(data), expires);
 }
 
-function set_background(url, descurl, imgwidth, imgheight) {
+function set_background(filename, url, descurl, imgwidth, imgheight) {
     var s = get_window_size();
     var winwidth = s[0];
     var winheight = s[1];
diff --git a/toolserver/settings.py b/toolserver/settings.py
index b42fd35..80f9f5c 100644
--- a/toolserver/settings.py
+++ b/toolserver/settings.py
@@ -11,9 +11,9 @@ def main(context, environ, headers):
     cookies = parse_cookies(context, environ)
 
     if query.action == "set":
-        status = _do_set(query, cookies)
+        status = _do_set(query, cookies, headers)
     elif query.action == "delete":
-        status = _do_delete(query, cookies)
+        status = _do_delete(query, cookies, headers)
     else:
         status = None
 
@@ -21,7 +21,7 @@ def main(context, environ, headers):
     langs, projects = get_sites(bot)
     return bot, cookies, status, langs, projects
 
-def _do_set(query, cookies):
+def _do_set(query, cookies, headers):
     changes = set()
     if query.lang:
         key = "EarwigDefaultLang"
@@ -38,7 +38,7 @@ def _do_set(query, cookies):
         return "Updated {0}.".format(changes)
     return None
 
-def _do_delete(query, cookies):
+def _do_delete(query, cookies, headers):
     if query.cookie in cookies:
         delete_cookie(headers, cookies, query.cookie.encode("utf8"))
         template = "Deleted cookie <b><tt>{0}</tt></b>."