diff --git a/themes/bootstrap3/js/cart.js b/themes/bootstrap3/js/cart.js
index cacf52b22ecdd01f3029807bbf979100db1b1018..4ae751100082ebf9ca4766aa4af799ea57900eb7 100644
--- a/themes/bootstrap3/js/cart.js
+++ b/themes/bootstrap3/js/cart.js
@@ -36,7 +36,7 @@ function getFullCartItems() {
 
 function addItemToCart(id,source) {
   if(!source) {
-    source = 'VuFind';
+    source = VuFind.getDefaultSearchBackend();
   }
   var cartItems = getCartItems();
   var cartSources = getCartSources();
diff --git a/themes/bootstrap3/js/common.js b/themes/bootstrap3/js/common.js
index 6ec9358ddd7a774a20c125fecd2ebfa93f444107..ae597c91b790e4817c91032aeb7349c71ea8630e 100644
--- a/themes/bootstrap3/js/common.js
+++ b/themes/bootstrap3/js/common.js
@@ -1,13 +1,16 @@
 /*global btoa, console, hexEncode, isPhoneNumberValid, Lightbox, rc4Encrypt, unescape, VuFind */
 
-function VuFindNamespace(p, s) {
+function VuFindNamespace(p, s, dsb) {
+  var defaultSearchBackend = dsb;
   var path = p;
   var strings = s;
 
+  var getDefaultSearchBackend = function() { return defaultSearchBackend; };
   var getPath = function() { return path; };
   var translate = function(op) { return strings[op] || op; };
 
   return {
+    getDefaultSearchBackend: getDefaultSearchBackend,
     getPath: getPath,
     translate: translate
   };
diff --git a/themes/bootstrap3/templates/layout/layout.phtml b/themes/bootstrap3/templates/layout/layout.phtml
index 46ae0fcf2432bd4c5c50adf5d407a5fbe14d937a..05f797740b384b9fa526a2de721395bbcb557c20 100644
--- a/themes/bootstrap3/templates/layout/layout.phtml
+++ b/themes/bootstrap3/templates/layout/layout.phtml
@@ -98,7 +98,8 @@
     <?
       $root = rtrim($this->url('home'), '/');
       $translations = $this->jsTranslations()->getJSON();
-      $setupJS = "var VuFind = new VuFindNamespace('{$root}', {$translations});";
+      $dsb = DEFAULT_SEARCH_BACKEND;
+      $setupJS = "var VuFind = new VuFindNamespace('{$root}', {$translations}, '{$dsb}');";
       $this->headScript()->appendScript($setupJS);
     ?>
     <?=$this->headScript()?>