diff --git a/src/api/src/backend/views/ETLPipelines.py b/src/api/src/backend/views/ETLPipelines.py
index b8221a7b..0b9f5e82 100644
--- a/src/api/src/backend/views/ETLPipelines.py
+++ b/src/api/src/backend/views/ETLPipelines.py
@@ -225,7 +225,7 @@ def post(self, request, group_id, *_, **__):
                         "output_id": "ACTIVE_MANIFEST"
                     }
                 },
-                None
+                "null"
             ]
         }