diff --git a/.docker-compose.http.yml b/.docker-compose.http.yml
index c38952b..d8ff6df 100644
--- a/.docker-compose.http.yml
+++ b/.docker-compose.http.yml
@@ -29,7 +29,7 @@ services:
       OAUTH_KEYCLOAK_CLIENT_SECRET: <clientsecret>
       OAUTH_KEYCLOAK_SERVER: <httpMethod>://<clientUrl>/keycloak
       OAUTH_KEYCLOAK_REALM: opendatenschutzcenter
-      MAILER_DSN: smtp://null
+      MAILER_DSN: null://null
       laF_version: 3.0.4
       demo_installation: demo
     labels:
diff --git a/.docker-compose.https.yml b/.docker-compose.https.yml
index e525336..b566785 100644
--- a/.docker-compose.https.yml
+++ b/.docker-compose.https.yml
@@ -59,7 +59,7 @@ services:
       OAUTH_KEYCLOAK_CLIENT_SECRET: <clientsecret>
       OAUTH_KEYCLOAK_SERVER: <clientUrl>/keycloak
       OAUTH_KEYCLOAK_REALM: opendatenschutzcenter
-      MAILER_DSN: smtp://null
+      MAILER_DSN: null://null
       laF_version: 3.0.4
       demo_installation: demo
     labels: