diff --git a/roles/matrix-bridge-appservice-webhooks/defaults/main.yml b/roles/matrix-bridge-appservice-webhooks/defaults/main.yml
index a317af18..cd675162 100644
--- a/roles/matrix-bridge-appservice-webhooks/defaults/main.yml
+++ b/roles/matrix-bridge-appservice-webhooks/defaults/main.yml
@@ -94,7 +94,7 @@ matrix_appservice_webhooks_registration_yaml: |
   namespaces:
     users:
       - exclusive: true
-        regex: '@{{ matrix_appservice_webhooks_user_prefix }}.*'
+        regex: '@{{ matrix_appservice_webhooks_user_prefix }}*:{{ matrix_domain }}'
     aliases: []
     rooms: []
   url: "{{ matrix_appservice_webhooks_appservice_url }}:{{ matrix_appservice_webhooks_matrix_port }}"