diff --git a/flippy.services.yml b/flippy.services.yml
index 9c38ad9..5112ab0 100644
--- a/flippy.services.yml
+++ b/flippy.services.yml
@@ -2,7 +2,7 @@ services:
   flippy.pager:
     class: Drupal\flippy\FlippyPager
     arguments:
-      - @entity_field.manager
-      - @event_dispatcher
+      - '@entity_field.manager'
+      - '@event_dispatcher'
   flippy.event:
     class: Drupal\flippy\FlippyEvent