diff --git a/charts/README.md b/charts/README.md
index d74419e80..7f9c11540 100644
--- a/charts/README.md
+++ b/charts/README.md
@@ -5,7 +5,7 @@ This is a minimal Helm chart for deploying the TREK app.
 ## Features
 - Deploys the TREK container
 - Exposes port 3000 via Service
-- Optional persistent storage for `/app/data` and `/app/uploads` and extra volumes support
+- Optional persistent storage for `/app/data` and `/app/uploads`, plus extra volumes and mounts
 - Configurable environment variables and secrets
 - Optional generic Ingress support
 - Configurable health checks (liveness/readiness probes) on `/api/health`
diff --git a/wiki/Install-Helm.md b/wiki/Install-Helm.md
index dd38efbc5..b1a1cab76 100644
--- a/wiki/Install-Helm.md
+++ b/wiki/Install-Helm.md
@@ -231,6 +231,21 @@ extraEnvFrom:
       name: trek-smtp
 ```
 
+### Further volumes
+
+`extraVolumes` adds volumes to the pod, and `extraVolumeMounts` mounts them in the TREK container, next to `/app/data` and `/app/uploads`. Both go into the Deployment as written, and the chart does not create the objects they name. For example, to give the booking import your own KItinerary extractors from a ConfigMap (one `.json` and one `.js` key for each extractor, see [Reservations-and-Bookings](Reservations-and-Bookings#your-own-extractors)):
+
+```yaml
+extraVolumes:
+  - name: kitinerary-extractors
+    configMap:
+      name: trek-kitinerary-extractors
+extraVolumeMounts:
+  - name: kitinerary-extractors
+    mountPath: /usr/local/share/kitinerary/extractors
+    readOnly: true
+```
+
 ### Ingress
 
 ```yaml
diff --git a/wiki/Reservations-and-Bookings.md b/wiki/Reservations-and-Bookings.md
index 6b8719ed2..1ea267b7a 100644
--- a/wiki/Reservations-and-Bookings.md
+++ b/wiki/Reservations-and-Bookings.md
@@ -216,7 +216,7 @@ services:
       - ./extractors:/usr/local/share/kitinerary/extractors:ro
 ```
 
-With the Helm chart, mount a ConfigMap there with `extraVolumes` and `extraVolumeMounts`. See the example in the chart's `values.yaml`.
+With the Helm chart, mount a ConfigMap there with `extraVolumes` and `extraVolumeMounts`. See [Install-Helm](Install-Helm#further-volumes).
 
 ### Review mark