diff --git a/core/core.services.yml b/core/core.services.yml
index e1ef8d2..cb1dc30 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -203,7 +203,7 @@ services:
     tags:
       - { name: service_collector, tag: page_cache_request_policy, call: addPolicy}
   page_cache_response_policy:
-    class: Drupal\Core\PageCache\ChainResponsePolicy
+    class: \Drupal\Core\PageCache\ChainResponsePolicy
     tags:
       - { name: service_collector, tag: page_cache_response_policy, call: addPolicy}
     lazy: true