diff --git a/app/assets/javascripts/application-legacy.js b/app/assets/javascripts/application-legacy.js
index 87a317e3b..66daa3767 100644
--- a/app/assets/javascripts/application-legacy.js
+++ b/app/assets/javascripts/application-legacy.js
@@ -804,7 +804,10 @@ function observeSearchfield(fieldId, targetId, url, options) {
     var checkedValues = {};
     var cbSelector = options && options.checkboxSelector;
     var $form = cbSelector ? $this.closest('form') : null;
-    var cbName = cbSelector ? $form.find(cbSelector).first().attr('name') : null;
+    function checkboxName() {
+      if (!cbSelector) return null;
+      return $form.find(cbSelector).first().attr('name');
+    }
 
     function saveChecked() {
       if (!cbSelector) return;
@@ -827,6 +830,7 @@ function observeSearchfield(fieldId, targetId, url, options) {
       });
       // Sync hidden inputs for checked values not visible as checkboxes
       $form.find('input.hidden-checked-value').remove();
+      var cbName = checkboxName();
       if (!cbName) return;
       $.each(checkedValues, function(val) {
         if ($form.find(cbSelector + '[value="' + val + '"]').length === 0) {