diff --git a/manifests/init.pp b/manifests/init.pp
index c3d0b3d..c8335e9 100644
--- a/manifests/init.pp
+++ b/manifests/init.pp
@@ -353,7 +353,7 @@ class cloudkitty(
     file {'metrics.yml':
       ensure  => present,
       path    => $::cloudkitty::params::metrics_yaml,
-      content => to_yaml($metrics_config),
+      content => stdlib::to_yaml($metrics_config),
       mode    => '0640',
       owner   => 'root',
       group   => $::cloudkitty::params::group,
diff --git a/metadata.json b/metadata.json
index a316996..967e117 100644
--- a/metadata.json
+++ b/metadata.json
@@ -11,7 +11,7 @@
         },
         {
             "name": "puppetlabs/stdlib",
-            "version_requirement": ">=5.0.0 <10.0.0"
+            "version_requirement": ">=9.0.0 <10.0.0"
         },
         {
             "name": "openstack/openstacklib",