diff --git a/templates/nagios/cgi_cfg.erb b/templates/nagios/cgi_cfg.erb
index e4f2a7c..fbfe505 100644
--- a/templates/nagios/cgi_cfg.erb
+++ b/templates/nagios/cgi_cfg.erb
@@ -30,9 +30,9 @@ authorized_for_all_hosts=<%= @ng_main_user %>,<%= @ng_hostview_auth %>
 authorized_for_all_service_commands=<%= @ng_main_user %>,<%= @ng_svc_cmd_auth %>
 authorized_for_all_host_commands=<%= @ng_main_user %>,<%= @ng_host_cmd_auth %>
 
-<% unless @ng_readonly_auth.empty? -%>
+<% unless @ng_readonly_auth.undef? -%>
 authorized_for_read_only=<%= @ng_readonly_auth %>
 <% end -%>
-<% unless @ng_statusmap_img.empty? -%>
+<% unless @ng_statusmap_img.undef? -%>
 statusmap_background_image=<%= @ng_statusmap_img %>
 <% end -%>