diff --git a/utils.py b/utils.py
index 0540e0f..33c45b0 100644
--- a/utils.py
+++ b/utils.py
@@ -314,6 +314,7 @@ def change_firewall(router_ports, main_ports, execute=None):
     else:
         main_ports.add(22)  # always add ssh
         if execute:
+            FIREWALL_MAIN.parent.mkdir(parents=True, exist_ok=True)
             with open(FIREWALL_MAIN, 'w') as fil:
                 fil.write(' '.join(str(p) for p in sorted(main_ports)))
                 fil.write('\n')