diff --git a/mkosi.images/system/mkosi.conf.d/10-ubuntu/mkosi.conf b/mkosi.images/system/mkosi.conf.d/10-ubuntu/mkosi.conf
index 25957b1e92..86f9736ed9 100644
--- a/mkosi.images/system/mkosi.conf.d/10-ubuntu/mkosi.conf
+++ b/mkosi.images/system/mkosi.conf.d/10-ubuntu/mkosi.conf
@@ -3,9 +3,6 @@
 [Match]
 Distribution=ubuntu
 
-[Distribution]
-PackageManagerTrees=noble-backports.sources:/etc/apt/sources.list.d/noble-backports.sources
-
 [Content]
 Packages=
         linux-image-generic
diff --git a/mkosi.images/system/mkosi.conf.d/10-ubuntu/mkosi.conf.d/non-x86.conf b/mkosi.images/system/mkosi.conf.d/10-ubuntu/mkosi.conf.d/non-x86.conf
new file mode 100644
index 0000000000..0ec4807822
--- /dev/null
+++ b/mkosi.images/system/mkosi.conf.d/10-ubuntu/mkosi.conf.d/non-x86.conf
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+# The ports Ubuntu archive is for non i386/amd64 repositories
+
+[Match]
+Architecture=!x86-64
+Architecture=!x86
+
+[Distribution]
+PackageManagerTrees=noble-backports-ports.sources:/etc/apt/sources.list.d/noble-backports-ports.sources
diff --git a/mkosi.images/system/mkosi.conf.d/10-ubuntu/mkosi.conf.d/x86.conf b/mkosi.images/system/mkosi.conf.d/10-ubuntu/mkosi.conf.d/x86.conf
new file mode 100644
index 0000000000..c08eeac337
--- /dev/null
+++ b/mkosi.images/system/mkosi.conf.d/10-ubuntu/mkosi.conf.d/x86.conf
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+# The main Ubuntu archive is only for i386/amd64 repositories
+
+[Match]
+Architecture=|x86-64
+Architecture=|x86
+
+[Distribution]
+PackageManagerTrees=noble-backports.sources:/etc/apt/sources.list.d/noble-backports.sources
diff --git a/mkosi.images/system/mkosi.conf.d/10-ubuntu/noble-backports-ports.sources b/mkosi.images/system/mkosi.conf.d/10-ubuntu/noble-backports-ports.sources
new file mode 100644
index 0000000000..5b96dc544d
--- /dev/null
+++ b/mkosi.images/system/mkosi.conf.d/10-ubuntu/noble-backports-ports.sources
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+Types: deb
+URIs: http://ports.ubuntu.com
+Suites: noble-backports
+Components: main universe
+Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg