diff --git a/roles/docker/defaults/main.yml b/roles/docker/defaults/main.yml
index 8bc38ef..9bf8bef 100644
--- a/roles/docker/defaults/main.yml
+++ b/roles/docker/defaults/main.yml
@@ -15,3 +15,6 @@ passit:
 
 fider:
   domain: "feedback.{{ base_domain }}"
+
+matrix:
+  domain: "matrix.{{ base_domain }}"
diff --git a/roles/docker/tasks/services/matrix_riot.yml b/roles/docker/tasks/services/matrix_riot.yml
index 0b19bf4..07897dd 100644
--- a/roles/docker/tasks/services/matrix_riot.yml
+++ b/roles/docker/tasks/services/matrix_riot.yml
@@ -13,7 +13,7 @@
     name: matrix
     image: matrixdotorg/synapse:latest
     env:
-      SYNAPSE_SERVER_NAME: my.matrix.host
+      SYNAPSE_SERVER_NAME: {{ matrix.domain }}
       SYNAPSE_REPORT_STATS: no
       SYNAPSE_ENABLE_REGISTRATION: yes
       SYNAPSE_LOG_LEVEL: INFO