diff --git a/site-modules/profile/manifests/swh/apt_config/backports.pp b/site-modules/profile/manifests/swh/apt_config/backports.pp
index 25314024..08627009 100644
--- a/site-modules/profile/manifests/swh/apt_config/backports.pp
+++ b/site-modules/profile/manifests/swh/apt_config/backports.pp
@@ -1,35 +1,30 @@
 # Configure apt pinning for packages we always want from backports
 class profile::swh::apt_config::backports {
-  $backported_packages = lookup('swh::apt_config::backported_packages', {
-    merge => {
-      strategy           => deep,
-      sort_merged_arrays => true,
-    },
-  })
+  $backported_packages = lookup('swh::apt_config::backported_packages', Hash, 'deep')
   $pinned_packages = $backported_packages[$::lsbdistcodename]
   if $pinned_packages {
     ::apt::pin {'swh-backported-packages':
       explanation => 'Pin packages backports',
       codename    => "${::lsbdistcodename}-backports",
       packages    => $pinned_packages,
       priority    => 990,
     }
   } else {
     ::apt::pin {'swh-backported-packages':
       ensure => absent,
     }
   }
 
   if $::lsbdistcodename != 'sid' {
     class {'::apt::backports':
       pin      => 100,
       location => $profile::swh::apt_config::debian_mirror,
       repos    => $profile::swh::apt_config::repos,
     }
   }
   else {
     ::apt::source {['backports', 'debian-updates', 'debian-security']:
       ensure => absent,
     }
   }
 }