diff --git a/host-pottwal.yml b/host-pottwal.yml
index 5460baa..41c9db1 100644
--- a/host-pottwal.yml
+++ b/host-pottwal.yml
@@ -42,6 +42,7 @@
         # RabbitMQ setup can be found in the inventory
     - role: netz39.matrix_synapse
       vars:
+        matrix_host_name: netz39.de
         matrix_data_path: "{{ data_dir }}/matrix/data"
         matrix_media_path: "{{ data_dir }}/matrix/media"
         matrix_postgres_data_path: "{{ data_dir }}/matrix/postgres"