diff --git a/manifests/swh/apt_config.pp b/manifests/swh/apt_config.pp
index 42a16a6..c3a0fb4 100644
--- a/manifests/swh/apt_config.pp
+++ b/manifests/swh/apt_config.pp
@@ -1,49 +1,50 @@
 # Base class for Software Heritage-specific apt configuration
 
 class profile::swh::apt_config {
   $debian_mirror = hiera('swh::apt_config::debian_mirror')
   $debian_security_mirror = hiera('swh::apt_config::debian_security_mirror')
 
   class {'::apt':
     purge => {
       'sources.list'   => true,
       'sources.list.d' => false,
       'preferences'    => true,
       'preferences.d'  => true,
     },
   }
 
   ::apt::source {'debian':
     location => $debian_mirror,
     release  => $::lsbdistcodename,
     repos    => 'main',
   }
 
   ::apt::source {'debian-updates':
     location => $debian_mirror,
     release  => "${::lsbdistcodename}-updates",
     repos    => 'main',
   }
 
   ::apt::source {'debian-security':
     location => $debian_security_mirror,
     release  => "${::lsbdistcodename}/updates",
     repos    => 'main',
   }
 
   class {'::apt::backports':
-    pin => 100,
+    pin      => 100,
+    location => $debian_mirror,
   }
 
   $swh_repository = hiera('swh::apt_config::swh_repository')
   ::apt::source {'softwareheritage':
     comment        => 'Software Heritage specific package repository',
     location       => $swh_repository,
     release        => $::lsbdistcodename,
     repos          => 'main',
     allow_unsigned => true,
   }
 
   Class['apt::update'] -> Package <||>
 
 }