diff --git a/.forgejo/workflows/ci.yaml b/.forgejo/workflows/ci.yaml
index bd65f57d..be39a2f2 100644
--- a/.forgejo/workflows/ci.yaml
+++ b/.forgejo/workflows/ci.yaml
@@ -43,7 +43,7 @@ jobs:
     runs-on: native
     steps:
       - uses: actions/checkout@v4
-      - run: nix build .#checks.x86_64-linux.deployment-basic -L
+      - run: cd deployment && nix-build -A tests
 
   check-deployment-cli:
     runs-on: native
diff --git a/deployment/check/basic/nixosTest.nix b/deployment/check/basic/nixosTest.nix
index 93c8ad23..6ffcb612 100644
--- a/deployment/check/basic/nixosTest.nix
+++ b/deployment/check/basic/nixosTest.nix
@@ -1,5 +1,8 @@
-{ inputs, lib, ... }:
-
+{
+  lib,
+  sources ? import ../npins,
+  ...
+}:
 {
   _class = "nixosTest";
 
@@ -11,18 +14,8 @@
   ];
 
   nodes.deployer =
-    { pkgs, ... }:
+    { nodes, ... }:
     {
-      environment.systemPackages = [
-        inputs.nixops4.packages.${pkgs.system}.default
-      ];
-
-      # FIXME: sad times
-      system.extraDependencies = with pkgs; [
-        jq
-        jq.inputDerivation
-      ];
-
       system.extraDependenciesFromModule =
         { pkgs, ... }:
         {
@@ -30,19 +23,60 @@
             hello
             cowsay
           ];
+
+          virtualisation = {
+            ## Memory use is expected to be dominated by the NixOS evaluation,
+            ## which happens on the deployer.
+            memorySize = 4096;
+            diskSize = 10 * 1024;
+            cores = 2;
+          };
+
+          nix.settings = {
+            substituters = lib.mkForce [ ];
+            hashed-mirrors = null;
+            connect-timeout = 1;
+          };
+
+          system.extraDependencies =
+            with pkgs;
+            [
+              jq
+              jq.inputDerivation
+              sources.nixpkgs
+
+              pkgs.stdenv
+              pkgs.stdenvNoCC
+
+              pkgs.cowsay
+              pkgs.cowsay.inputDerivation # NOTE: Crucial!!!
+
+              ## Some derivations will be different compared to target's initial
+              ## state, so we'll need to be able to build something similar.
+              ## Generally the derivation inputs aren't that different, so we
+              ## use the initial state of the target as a base.
+              nodes.target.system.build.toplevel.inputDerivation
+              nodes.target.system.build.etc.inputDerivation
+              nodes.target.system.path.inputDerivation
+              nodes.target.system.build.bootStage1.inputDerivation
+              nodes.target.system.build.bootStage2.inputDerivation
+            ]
+            ++ lib.concatLists (
+              lib.mapAttrsToList (
+                _k: v: if v ? source.inputDerivation then [ v.source.inputDerivation ] else [ ]
+              ) nodes.target.environment.etc
+            );
         };
     };
 
   extraTestScript = ''
     with subtest("Check the status before deployment"):
-      hello.fail("hello 1>&2")
-      cowsay.fail("cowsay 1>&2")
+      target.fail("cowsay hi 1>&2")
 
     with subtest("Run the deployment"):
-      deployer.succeed("nixops4 apply check-deployment-basic --show-trace --no-interactive 1>&2")
+      deployer.succeed("cd work && tofu apply --show-trace --no-interactive")
 
     with subtest("Check the deployment"):
-      hello.succeed("hello 1>&2")
-      cowsay.succeed("cowsay hi 1>&2")
+      target.succeed("cowsay hi 1>&2")
   '';
 }
diff --git a/deployment/default.nix b/deployment/default.nix
index c76489bd..f4ca894f 100644
--- a/deployment/default.nix
+++ b/deployment/default.nix
@@ -1,3 +1,4 @@
+<<<<<<< HEAD
 ## `makeMakeDeployment` -- Function to help hosting providers make a
 ## `makeDeployment` function.
 ##
@@ -214,5 +215,17 @@ in
           }
         );
       };
+=======
+{
+  system ? builtins.currentSystem,
+  sources ? import ../npins,
+  pkgs ? import sources.nixpkgs {
+    inherit system;
+  },
+}:
+{
+  tests = {
+    deployment-basic = import ./check/basic/nixosTest.nix { inherit pkgs; };
+>>>>>>> fac372b3 (strip test as a start to convert it)
   };
 }
diff --git a/infra/sync-nix/.npins.json b/infra/sync-nix/.npins.json
deleted file mode 100644
index e679cf7e..00000000
--- a/infra/sync-nix/.npins.json
+++ /dev/null
@@ -1 +0,0 @@
-{"agenix":"/nix/store/glsqq1xn5al7d528hvlbm4hl3ladxmka-source","disko":"/nix/store/7wf9q0mb1i43x9dr1qlyfaraq15n6sii-source","flake-inputs":"/nix/store/fqln0bcp6mp75k4sl0cav2f0np60lwhj-source","git-hooks":"/nix/store/8bh3jgq1riy3jxm07vy4xxzvk9xd74pc-source","gitignore":"/nix/store/g5v3sgqy6a0fsmas7mnapc196flrplix-source","home-manager":"/nix/store/cq3b3cx5rv9d0zj57kch9wmxzc2rm8dc-source","htmx":"/nix/store/mwqqk0qmldzvv4xj9kq2lbah2flhc44z-source","nix-unit":"/nix/store/4g1vvy7bhwh16cyd2r8ibq7n6ygk1wvk-source","nixpkgs":"/nix/store/w0y3wsqi67rlg544myycqxcg2hh17j1v-source"}