diff --git a/manifests/init.pp b/manifests/init.pp
index cd408d8f67..a769ea7bf4 100644
--- a/manifests/init.pp
+++ b/manifests/init.pp
@@ -200,7 +200,7 @@
     assert_type(Integer, $update['tries'])
   }
 
-  $_update = merge($apt::update_defaults, $update)
+  $_update = Stdlib.merge($apt::update_defaults, $update)
   include apt::update
 
   if $purge['sources.list'] {
@@ -222,11 +222,11 @@
     assert_type(Boolean, $purge['apt.conf.d'])
   }
 
-  $_purge = merge($apt::purge_defaults, $purge)
+  $_purge = Stdlib.merge($apt::purge_defaults, $purge)
 
   if $proxy['perhost'] {
     $_perhost = $proxy['perhost'].map |$item| {
-      $_item = merge($apt::proxy_defaults, $item)
+      $_item = Stdlib.merge($apt::proxy_defaults, $item)
       $_scheme = $_item['https'] ? {
         true    => 'https',
         default => 'http',
@@ -239,7 +239,7 @@
         true    => 'DIRECT',
         default => "${_scheme}://${_item['host']}${_port}/",
       }
-      merge($item, {
+      stdib::merge($item, {
           'scheme' => $_scheme,
           'target' => $_target,
         }
@@ -249,7 +249,7 @@
     $_perhost = {}
   }
 
-  $_proxy = merge($apt::proxy_defaults, $proxy, { 'perhost' => $_perhost })
+  $_proxy = Stdlib.merge($apt::proxy_defaults, $proxy, { 'perhost' => $_perhost })
 
   $confheadertmp = epp('apt/_conf_header.epp')
   $proxytmp = epp('apt/proxy.epp', { 'proxies' => $_proxy })
diff --git a/metadata.json b/metadata.json
index 076f068de1..48487aaa50 100644
--- a/metadata.json
+++ b/metadata.json
@@ -10,7 +10,7 @@
   "dependencies": [
     {
       "name": "puppetlabs/stdlib",
-      "version_requirement": ">= 4.16.0 < 9.0.0"
+      "version_requirement": ">= 4.16.0 < 10.0.0"
     }
   ],
   "operatingsystem_support": [