config dhcp hosts only when hosts are defined
diff --git a/isc_dhcp/files/dhcpd.hosts b/isc_dhcp/files/dhcpd.hosts
index 359e5b1..8a4292f 100644
--- a/isc_dhcp/files/dhcpd.hosts
+++ b/isc_dhcp/files/dhcpd.hosts
@@ -1,5 +1,6 @@
 {%- from "isc_dhcp/map.jinja" import server with context %}
 
+{%- if server.host is defined %}
 {%- for host_name, host in server.host.iteritems() %}
 
 host {{ host_name }} {
@@ -11,3 +12,5 @@
 }
 
 {%- endfor %}
+{%- endif %}
+