core/lib/Drupal/Core/Cache/QueryArgsCacheContext.php | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/core/lib/Drupal/Core/Cache/QueryArgsCacheContext.php b/core/lib/Drupal/Core/Cache/QueryArgsCacheContext.php
index 484b971..4c34721 100644
--- a/core/lib/Drupal/Core/Cache/QueryArgsCacheContext.php
+++ b/core/lib/Drupal/Core/Cache/QueryArgsCacheContext.php
@@ -31,9 +31,7 @@ public function getContext($query_arg = NULL) {
       return $this->requestStack->getCurrentRequest()->getQueryString();
     }
     else {
-      $query_args = [];
-      parse_str($this->requestStack->getCurrentRequest()->getQueryString(), $query_args);
-      return $query_arg . '.' . (isset($query_args[$query_arg]) ? $query_args[$query_arg] : '');
+      return $this->requestStack->getCurrentRequest()->query->get($query_arg);
     }
   }