diff --git a/testing/deployments/hub.yaml b/testing/deployments/hub.yaml
index 264c85c912d9f5b6790544e2b9802e52c56de2e1..d87dd9856bdfad4d5a0cf19853ffb8999a6ddf86 100644
--- a/testing/deployments/hub.yaml
+++ b/testing/deployments/hub.yaml
@@ -154,18 +154,22 @@ hub:
       admin_access: true
       authenticate_prometheus: false
       authenticator_class: egi_notebooks_hub.egiauthenticator.EGICheckinAuthenticator
-      services:
-        - name: 'jupyterhub-idle-culler-service'
-          admin: true
-          command:
-            - python3
-            - -m
-            - jupyterhub_idle_culler
-            - --timeout=600
-            - --cull-users=True
-            - --remove-named-servers=True
       # spawner_class: (in egi-notebooks-b2drop)
   extraConfig:
+    define-idle-culler-service: |-
+      c.JupyterHub.services = [
+      {
+        "name": "jupyterhub-idle-culler-service",
+        "command": [
+            sys.executable,
+            "-m", "jupyterhub_idle_culler",
+            "--timeout=600",
+            "--cull-users=True",
+            "--remove-named-servers=True"
+        ],
+        "admin": True,
+        }
+        ]
     assign-roles-culler: |-
       c.JupyterHub.load_roles = [
       {
@@ -177,7 +181,7 @@ hub:
               "read:servers",
               "delete:servers",
               "admin:users", # if using --cull-users (to delete users)
-          ],
+          ]
       }
       ]
     egi-notebooks-welcome: |-