diff --git a/checks/installation/flake-module.nix b/checks/installation/flake-module.nix
index ce0dbacb0..f48c4e040 100644
--- a/checks/installation/flake-module.nix
+++ b/checks/installation/flake-module.nix
@@ -7,8 +7,8 @@
 {
   clan.machines.test-install-machine = {
     clan.core.networking.targetHost = "test-install-machine";
-    fileSystems."/".device = lib.mkDefault "/dev/vdb";
-    boot.loader.grub.device = lib.mkDefault "/dev/vdb";
+    fileSystems."/".device = lib.mkDefault "/dev/vda";
+    boot.loader.grub.device = lib.mkDefault "/dev/vda";
 
     imports = [ self.nixosModules.test-install-machine ];
   };
@@ -22,7 +22,7 @@
           (modulesPath + "/profiles/qemu-guest.nix")
           ../lib/minify.nix
         ];
-        clan.single-disk.device = "/dev/vdb";
+        clan.single-disk.device = "/dev/vda";
 
         environment.etc."install-successful".text = "ok";
 
@@ -47,7 +47,6 @@
         pkgs.nixos-anywhere
       ] ++ builtins.map (i: i.outPath) (builtins.attrValues self.inputs);
       closureInfo = pkgs.closureInfo { rootPaths = dependencies; };
-      qemu-common = import "${inputs.nixpkgs}/nixos/lib/qemu-common.nix" { inherit lib pkgs; };
     in
     {
       # On aarch64-linux, hangs on reboot with after installation:
@@ -64,22 +63,41 @@
           name = "test-installation";
           nodes.target = {
             services.openssh.enable = true;
-            users.users.root.openssh.authorizedKeys.keyFiles = [ ../lib/ssh/pubkey ];
-            system.nixos.variant_id = "installer";
-            environment.systemPackages = [ pkgs.nixos-facter ];
-            virtualisation.emptyDiskImages = [ 4096 ];
-            nix.settings = {
-              substituters = lib.mkForce [ ];
-              hashed-mirrors = null;
-              connect-timeout = lib.mkForce 3;
-              flake-registry = pkgs.writeText "flake-registry" ''{"flakes":[],"version":2}'';
-              experimental-features = [
-                "nix-command"
-                "flakes"
-              ];
-            };
-            system.extraDependencies = dependencies;
+            virtualisation.diskImage = "./target.qcow2";
+            virtualisation.useBootLoader = true;
+
+            # virtualisation.fileSystems."/" = {
+            #   device = "/dev/disk/by-label/this-is-not-real-and-will-never-be-used";
+            #   fsType = "ext4";
+            # };
           };
+          nodes.installer =
+            { modulesPath, ... }:
+            {
+              imports = [
+                (modulesPath + "/../tests/common/auto-format-root-device.nix")
+              ];
+              services.openssh.enable = true;
+              users.users.root.openssh.authorizedKeys.keyFiles = [ ../lib/ssh/pubkey ];
+              system.nixos.variant_id = "installer";
+              environment.systemPackages = [ pkgs.nixos-facter ];
+              virtualisation.emptyDiskImages = [ 512 ];
+              virtualisation.diskSize = 8 * 1024;
+              virtualisation.rootDevice = "/dev/vdb";
+              # both installer and target need to use the same diskImage
+              virtualisation.diskImage = "./target.qcow2";
+              nix.settings = {
+                substituters = lib.mkForce [ ];
+                hashed-mirrors = null;
+                connect-timeout = lib.mkForce 3;
+                flake-registry = pkgs.writeText "flake-registry" ''{"flakes":[],"version":2}'';
+                experimental-features = [
+                  "nix-command"
+                  "flakes"
+                ];
+              };
+              system.extraDependencies = dependencies;
+            };
           nodes.client = {
             environment.systemPackages = [
               self.packages.${pkgs.system}.clan-cli
@@ -100,36 +118,28 @@
           };
 
           testScript = ''
-            def create_test_machine(oldmachine=None, args={}): # taken from <nixpkgs/nixos/tests/installer.nix>
-                startCommand = "${qemu-common.qemuBinary pkgs.qemu_test}"
-                startCommand += " -cpu max -m 1024 -virtfs local,path=/nix/store,security_model=none,mount_tag=nix-store"
-                startCommand += f' -drive file={oldmachine.state_dir}/empty0.qcow2,id=drive1,if=none,index=1,werror=report'
-                startCommand += ' -device virtio-blk-pci,drive=drive1'
-                machine = create_machine({
-                  "startCommand": startCommand,
-                } | args)
-                driver.machines.append(machine)
-                return machine
-
-            start_all()
+            client.start()
+            installer.start()
 
             client.succeed("${pkgs.coreutils}/bin/install -Dm 600 ${../lib/ssh/privkey} /root/.ssh/id_ed25519")
-            client.wait_until_succeeds("timeout 2 ssh -o StrictHostKeyChecking=accept-new -v root@target hostname")
+            client.wait_until_succeeds("timeout 2 ssh -o StrictHostKeyChecking=accept-new -v root@installer hostname")
             client.succeed("cp -r ${../..} test-flake && chmod -R +w test-flake")
             client.fail("test -f test-flake/machines/test-install-machine/hardware-configuration.nix")
-            client.succeed("clan machines update-hardware-config --flake test-flake test-install-machine root@target>&2")
+            client.succeed("clan machines update-hardware-config --flake test-flake test-install-machine root@installer >&2")
             client.succeed("test -f test-flake/machines/test-install-machine/hardware-configuration.nix")
-            client.succeed("clan machines update-hardware-config --backend nixos-facter --flake test-flake test-install-machine root@target>&2")
+            client.succeed("clan machines update-hardware-config --backend nixos-facter --flake test-flake test-install-machine root@installer>&2")
             client.succeed("test -f test-flake/machines/test-install-machine/facter.json")
-            client.succeed("clan machines install --debug --flake ${../..} --yes test-install-machine --target-host root@target >&2")
+            client.succeed("clan machines install --debug --flake ${../..} --yes test-install-machine --target-host root@installer >&2")
             try:
-              target.shutdown()
+              installer.shutdown()
             except BrokenPipeError:
               # qemu has already exited
               pass
 
-            new_machine = create_test_machine(oldmachine=target, args={ "name": "new_machine" })
-            assert(new_machine.succeed("cat /etc/install-successful").strip() == "ok")
+            target.state_dir = installer.state_dir
+            target.start()
+            target.wait_for_unit("multi-user.target")
+            assert(target.succeed("cat /etc/install-successful").strip() == "ok")
           '';
         } { inherit pkgs self; };
       };