diff --git a/group_vars/matrix_servers b/group_vars/matrix_servers
index 79df3cf16..1705bdebb 100755
--- a/group_vars/matrix_servers
+++ b/group_vars/matrix_servers
@@ -1078,6 +1078,14 @@ matrix_bot_maubot_systemd_required_services_list: |
     (['matrix-nginx-proxy.service'] if matrix_nginx_proxy_enabled else [])
   }}
 
+matrix_bot_maubot_registration_shared_secret: |-
+  {{
+    {
+      'synapse': matrix_synapse_registration_shared_secret,
+      'dendrite': matrix_dendrite_registration_shared_secret,
+    }[matrix_homeserver_implementation]
+  }}
+
 
 ######################################################################
 #
diff --git a/roles/matrix-bot-maubot/templates/config/config.yaml.j2 b/roles/matrix-bot-maubot/templates/config/config.yaml.j2
index 86f0076db..2797c03fe 100644
--- a/roles/matrix-bot-maubot/templates/config/config.yaml.j2
+++ b/roles/matrix-bot-maubot/templates/config/config.yaml.j2
@@ -77,7 +77,7 @@ homeservers:
     # registration_shared_secret from synapse config
     # You can leave this empty if you don't have access to the homeserver.
     # When this is empty, `mbc auth --register` won't work, but `mbc auth` (login) will.
-        secret: {{ matrix_registration_shared_secret }}
+        secret: {{ matrix_bot_maubot_registration_shared_secret|to_json }}
 
 # List of administrator users. Plaintext passwords will be bcrypted on startup. Set empty password
 # to prevent normal login. Root is a special user that can't have a password and will always exist.