diff --git a/manifest.yml.j2 b/manifest.yml.j2
index 3aba456fe..3acd561d8 100644
--- a/manifest.yml.j2
+++ b/manifest.yml.j2
@@ -65,7 +65,9 @@
   'notify-delivery-worker-retry-tasks': {},
   'notify-delivery-worker-internal': {},
   'notify-delivery-worker-broadcasts': {
+    'additional_env_vars': {
       'CELERYD_PREFETCH_MULTIPLIER': 1,
+    }
   },
   'notify-delivery-worker-receipts': {},
   'notify-delivery-worker-service-callbacks': {'disk_quota': '2G'},