diff --git a/templates/httpd/nagios_conf.erb b/templates/httpd/nagios_conf.erb
index 9f6324b..8337061 100644
--- a/templates/httpd/nagios_conf.erb
+++ b/templates/httpd/nagios_conf.erb
@@ -19,11 +19,11 @@ ScriptAlias /nagios/cgi-bin/ "/usr/lib64/nagios/cgi-bin/"
    <IfVersion >= 2.3>
       <RequireAll>
          Require all granted
-<% if @ng_required_hosts != undef -%>
+<% if @ng_required_hosts != '' -%>
 <% @ng_required_hosts.each do |required_host| -%>
          Require host <%= required_host %>
 <% end end -%>
-<% if @ng_required_ips != undef -%>
+<% if @ng_required_ips != '' -%>
 <% @ng_required_ips.each do |required_ips| -%>
          Require ip <%= required_ips %>
 <% end end -%>
@@ -56,11 +56,11 @@ Alias /nagios "/usr/share/nagios/html"
    <IfVersion >= 2.3>
       <RequireAll>
          Require all granted
-<% if @ng_required_hosts != undef -%>
+<% if @ng_required_hosts != '' -%>
 <% @ng_required_hosts.each do |required_host| -%>
          Require host <%= required_host %>
 <% end end -%>
-<% if @ng_required_ips != undef %>
+<% if @ng_required_ips != '' %>
 <% @ng_required_ips.each do |required_ips| -%>
          Require ip <%= required_ips %>
 <% end end -%>