diff --git a/manifests/init.pp b/manifests/init.pp
index d4a39c0..3359fb4 100644
--- a/manifests/init.pp
+++ b/manifests/init.pp
@@ -206,28 +206,28 @@ class kea (
   }
   file { '/etc/kea/kea-dhcp4.conf':
     ensure  => $ensure,
-    content => to_json_pretty($dhcp4_conf, nil, { indent => '  ' }),
+    content => to_json_pretty($dhcp4_conf, true, { indent => '  ' }),
     mode    => '0644',
     require => Package['kea'],
     notify  => Service[$services],
   }
   file { '/etc/kea/kea-dhcp6.conf':
     ensure  => $ensure,
-    content => to_json_pretty($dhcp6_conf, nil, { indent => '  ' }),
+    content => to_json_pretty($dhcp6_conf, true, { indent => '  ' }),
     mode    => '0644',
     require => Package['kea'],
     notify  => Service[$services],
   }
   file { '/etc/kea/kea-dhcp-ddns.conf':
     ensure  => $ensure,
-    content => to_json_pretty($ddns_conf, nil, { indent => '  ' }),
+    content => to_json_pretty($ddns_conf, true, { indent => '  ' }),
     mode    => '0644',
     require => Package['kea'],
     notify  => Service[$services],
   }
   file { '/etc/kea/kea-ctrl-agent.conf':
     ensure  => $ensure,
-    content => to_json_pretty($ctrl_agent_conf, nil, { indent => '  ' }),
+    content => to_json_pretty($ctrl_agent_conf, true, { indent => '  ' }),
     mode    => '0644',
     require => Package['kea'],
     notify  => Service[$services],