diff --git a/tasks/firewall.yaml b/tasks/firewall.yaml
index 1dd8bb1..c52725c 100644
--- a/tasks/firewall.yaml
+++ b/tasks/firewall.yaml
@@ -9,7 +9,7 @@
     - name: "set vars"
       ansible.builtin.set_fact:
         __firewall_enable: "{{ firewall_enable }}"
-        __firewall_all_rules: "{{ firewall_basic_rules | union(firewall_host_rules)}}"
+        __firewall_all_rules: "{{ firewall_basic_rules | union(firewall_host_rules | default[]) }}"
 
     # debugging
     - name: "debug"