diff --git a/scripts/deploy.sh b/scripts/deploy.sh
index 381364cc..11b4bb6b 100755
--- a/scripts/deploy.sh
+++ b/scripts/deploy.sh
@@ -1,3 +1,4 @@
 #!/usr/bin/env bash
-export CHATMAIL_DOMAIN="${1:-c1.testrun.org}"
+: ${CHATMAIL_DOMAIN:=c1.testrun.org}
+export CHATMAIL_DOMAIN
 chatmail-pyinfra/venv/bin/pyinfra --ssh-user root "$CHATMAIL_DOMAIN" deploy.py