diff --git a/includes/better_exposed_filters.theme.inc b/includes/better_exposed_filters.theme.inc
index 5c2db85..1dfcc60 100644
--- a/includes/better_exposed_filters.theme.inc
+++ b/includes/better_exposed_filters.theme.inc
@@ -204,8 +204,8 @@ function template_preprocess_bef_links(array &$variables) {
   // Clean existing query string in case of an ajax request.
   if (\Drupal::request()->isXmlHttpRequest()) {
     foreach (['ajax_page_state', '_wrapper_format'] as $parameter) {
-      if (isset($existingQuery[$parameter])) {
-        unset($existingQuery[$parameter]);
+      if (isset($existing_query[$parameter])) {
+        unset($existing_query[$parameter]);
       }
     }
   }