diff --git a/roles/mas/defaults/main.json b/roles/mas/defaults/main.json
index cbb1c0a..7e5ae2c 100644
--- a/roles/mas/defaults/main.json
+++ b/roles/mas/defaults/main.json
@@ -1,7 +1,7 @@
 {
 	"var_mas_user": "mas",
 	"var_mas_directory": "/opt/mas",
-	"var_mas_server_address": "::",
+	"var_mas_server_address": "[::]",
 	"var_mas_server_port": 2839,
 	"var_mas_database_host": "postgresql.example.org",
 	"var_mas_database_port": 5432,