diff --git a/metadata.json b/metadata.json
index 2871fc75..59fe7214 100644
--- a/metadata.json
+++ b/metadata.json
@@ -10,7 +10,7 @@
   "dependencies": [
     {
       "name": "puppetlabs/stdlib",
-      "version_requirement": ">= 4.13.1 < 9.0.0"
+      "version_requirement": ">= 9.0.0 < 10.0.0"
     }
   ],
   "operatingsystem_support": [
diff --git a/spec/acceptance/format_spec.rb b/spec/acceptance/format_spec.rb
index f0fa4298..3f48a320 100644
--- a/spec/acceptance/format_spec.rb
+++ b/spec/acceptance/format_spec.rb
@@ -95,12 +95,12 @@
 
         concat::fragment { '1':
           target  => '#{basedir}/file',
-          content => to_yaml([{ 'one.a' => 'foo', 'one.b' => 'bar' }]),
+          content => stdlib::to_yaml([{ 'one.a' => 'foo', 'one.b' => 'bar' }]),
         }
 
         concat::fragment { '2':
           target  => '#{basedir}/file',
-          content => to_yaml([{ 'two.a' => 'dip', 'two.b' => 'doot' }]),
+          content => stdlib::to_yaml([{ 'two.a' => 'dip', 'two.b' => 'doot' }]),
         }
       MANIFEST
     end