diff --git a/flake.nix b/flake.nix
index 060ae42..afaee98 100644
--- a/flake.nix
+++ b/flake.nix
@@ -9,6 +9,25 @@
     { self, nixpkgs }:
     {
       lib = {
+        # Prepare an update package for the system.
+        mkUpdate =
+          nixos:
+          let
+            config = nixos.config;
+            pkgs = nixpkgs.legacyPackages.x86_64-linux.pkgs;
+          in
+          nixos.pkgs.runCommand "update-${config.system.image.version}"
+            {
+              nativeBuildInputs = with pkgs; [ xz ];
+            }
+            ''
+              mkdir -p $out
+              xz -1 -cz ${config.system.build.uki}/${config.system.boot.loader.ukiFile} \
+                > $out/${config.system.boot.loader.ukiFile}.xz
+              xz -1 -cz ${config.system.build.image}/${config.boot.uki.name}_${config.system.image.version}.store.raw \
+                > $out/${config.boot.uki.name}_${config.system.image.version}.img.xz
+            '';
+
         # Prepare a ready-to-boot disk image.
         mkInstallImage =
           nixos:
@@ -39,8 +58,8 @@
 
       packages.x86_64-linux = {
         default = self.packages.x86_64-linux.patos_image;
-
         patos_image = self.lib.mkInstallImage self.nixosConfigurations.patos;
+        patos_update = self.lib.mkUpdate self.nixosConfigurations.patos;
 
         # A helper script to run the disk images above.
         qemu-efi =
@@ -71,5 +90,6 @@
           ];
         };
       };
+
     };
 }
diff --git a/modules/sysupdate.nix b/modules/sysupdate.nix
index ed9cf21..949fbcb 100644
--- a/modules/sysupdate.nix
+++ b/modules/sysupdate.nix
@@ -36,7 +36,7 @@
       "20-store" = {
         Source = {
           MatchPattern = [
-            "store_@v.img.xz"
+            "${config.boot.uki.name}_@v.img.xz"
           ];
           # Path = "https://download.example.com/";
           # Type = "url-file";
@@ -52,7 +52,7 @@
           # Path = "auto";
           Path = "/dev/sda";
 
-          MatchPattern = "store_@v";
+          MatchPattern = "${config.boot.uki.name}_@v";
 
           Type = "partition";
           ReadOnly = "yes";