diff --git a/docs/configuring-playbook-bridge-matrix-bridge-sms.md b/docs/configuring-playbook-bridge-matrix-bridge-sms.md
index 7f58a74cd..7768102c5 100644
--- a/docs/configuring-playbook-bridge-matrix-bridge-sms.md
+++ b/docs/configuring-playbook-bridge-matrix-bridge-sms.md
@@ -33,6 +33,14 @@ matrix_sms_bridge_provider_android_truststore_password: 123
 
 ```
 
+### Extending the configuration
+
+There are some additional things you may wish to configure about the bridge.
+
+Take a look at:
+
+- `roles/custom/matrix-bridge-sms/defaults/main.yml` for some variables that you can customize via your `vars.yml` file. You can override settings (even those that don't have dedicated playbook variables) using the `matrix_sms_bridge_configuration_extension_yaml` variable
+
 ## Installing
 
 After configuring the playbook, run it with [playbook tags](playbook-tags.md) as below: