diff --git a/manifests/nagios/objects/add_timeperiods.pp b/manifests/nagios/objects/add_timeperiods.pp
index d0b9efa..5c4579d 100644
--- a/manifests/nagios/objects/add_timeperiods.pp
+++ b/manifests/nagios/objects/add_timeperiods.pp
@@ -57,7 +57,7 @@ $ng_timep_thursday    = '00:00-00:00',
 $ng_timep_friday      = '00:00-00:00',
 $ng_timep_saturday    = '00:00-00:00',
 $ng_timep_sunday      = '00:00-00:00',
-$ng_timep_special_01  = undef,
+$ng_timep_special_01  = '',
 $ng_timep_special_02  = '00:00-00:00',
 
 ) {
diff --git a/templates/nagios/timeperiods_cfg_rule.erb b/templates/nagios/timeperiods_cfg_rule.erb
index d68ae52..1b17c8a 100644
--- a/templates/nagios/timeperiods_cfg_rule.erb
+++ b/templates/nagios/timeperiods_cfg_rule.erb
@@ -10,7 +10,7 @@ define timeperiod {
   saturday          <%= @ng_timep_saturday %>
   sunday            <%= @ng_timep_sunday %>
   }
-<% unless @ng_timep_special_01.empty? -%>
+<% unless @ng_timep_special.empty? -%>
 define timeperiod {
   timeperiod_name       <%= @ng_timeperiod_name %>
   @ng_timep_special_01