diff --git a/tests/compose/webmail/01_ensure_admin_unreachable.sh b/tests/compose/webmail/01_ensure_admin_unreachable.sh
index a3864b78..3351b85b 100755
--- a/tests/compose/webmail/01_ensure_admin_unreachable.sh
+++ b/tests/compose/webmail/01_ensure_admin_unreachable.sh
@@ -1,4 +1,6 @@
 #!/bin/bash
 
-[[ `curl -I -so /dev/null -w "%{http_code}" http://localhost/` -ne 200 ]] && echo "The default page of snappymail hasn't returned 200!" >>/dev/stderr && exit 1
-[[ `curl -I -so /dev/null -w "%{http_code}" http://localhost/?admin` -ne 403 ]] && echo "The admin of snappymail is not disabled!" >>/dev/stderr && exit 1
+IP="$(docker inspect webmail_webmail_1|jq '.[0].NetworkSettings.Networks.webmail_default.IPAddress')"
+
+[[ $(curl -I -so /dev/null -w "%{http_code}" http://$IP/) -ne 200 ]] && echo "The default page of snappymail hasn't returned 200!" >>/dev/stderr && exit 1
+[[ $(curl -I -so /dev/null -w "%{http_code}" http://$IP/?admin) -ne 403 ]] && echo "The admin of snappymail is not disabled!" >>/dev/stderr && exit 1