diff --git a/.env.sample b/.env.sample
index 58b1937..f9dbe1f 100644
--- a/.env.sample
+++ b/.env.sample
@@ -152,3 +152,4 @@ DB_FLAVOR=sqlite
 ###################################
 # COMPOSE_FILE="compose.yml:compose.mailman.yml"
 # MAILMAN_CORE_VOLUME=lists_example_com_mailman-core
+# MAILMAN_CORE_NETWORK=lists_example_com_internal