diff --git a/templates/primary_zone_config.j2 b/templates/primary_zone_config.j2
index a949584..09b47c2 100644
--- a/templates/primary_zone_config.j2
+++ b/templates/primary_zone_config.j2
@@ -1,6 +1,6 @@
 # Primary zone definition for {{ item.zone_name }}
 
-{% for slave in item.slaves %}
+{% for slave in item.slaves|default([]) %}
 {% if slave.tsig_secret is defined %}
 key:
     name: "{{ item.zone_name }}_{{ slave.ip }}"
@@ -16,7 +16,7 @@ key:
 zone:
   name: "{{ item.zone_name }}"
   zonefile: "{{ primary_zones_dir }}/{{ item.zone_filename }}"
-{% for slave in item.slaves %}
+{% for slave in item.slaves|default([]) %}
   notify: {{ slave.ip }} "{{ tsigkey(slave) }}"
   provide-xfr: {{ slave.ip }} "{{ tsigkey(slave) }}"
 {% endfor %}
diff --git a/templates/secondary_zone_config.j2 b/templates/secondary_zone_config.j2
index d468806..22a652c 100644
--- a/templates/secondary_zone_config.j2
+++ b/templates/secondary_zone_config.j2
@@ -1,6 +1,6 @@
 # Secondary zone definition for {{ item.zone_name }}
 
-{% for master in item.masters %}
+{% for master in item.masters|default([]) %}
 {% if master.tsig_secret is defined %}
 key:
     name: "{{ item.zone_name }}_{{ master.ip }}"
@@ -16,7 +16,7 @@ key:
 zone:
   name: "{{ item.zone_name }}"
   zonefile: "{{ secondary_zones_dir }}/{{ item.zone_name }}"
-{% for master in item.masters %}
+{% for master in item.masters|default([]) %}
   allow-notify: {{ master.ip }} "{{ tsigkey(master) }}"
   request-xfr: AXFR {{ master.ip }} "{{ tsigkey(master) }}"
 {% endfor %}