diff --git a/lib/refrepo/gen/puppet/network_monitoring.rb b/lib/refrepo/gen/puppet/network_monitoring.rb
index daccb0a31855f77839a2396bc5b52a3300baddd6..89f0ef49fb542c595f22882a530e1f753976751f 100644
--- a/lib/refrepo/gen/puppet/network_monitoring.rb
+++ b/lib/refrepo/gen/puppet/network_monitoring.rb
@@ -58,6 +58,8 @@ def generate_puppet_network_monitoring(options)
         puts "ERROR: multiple entry for #{fqdn_eq_name} in hiera"
       end
 
+      net_hosts_eq['interfaces'] ||= []
+
       eq_v['linecards'].each do |l|
         next if l == {}