diff --git a/.forgejo/workflows/Dockerfile b/.forgejo/workflows/Dockerfile
new file mode 100644
index 0000000..0d67148
--- /dev/null
+++ b/.forgejo/workflows/Dockerfile
@@ -0,0 +1,2 @@
+FROM nixos/nix
+ENTRYPOINT [ "/usr/bin/env" "sleep" "3600" ]
diff --git a/.forgejo/workflows/test.yml b/.forgejo/workflows/test.yml
index 17d83ac..5b46e73 100644
--- a/.forgejo/workflows/test.yml
+++ b/.forgejo/workflows/test.yml
@@ -7,8 +7,9 @@ jobs:
     runs-on: docker
     container:
       image: nixos/nix:2.16.1
-      entrypoint: /usr/bin/env sleep
     steps:
       - uses: actions/checkout@v3
-      - run: ls -l
-      - run: uname -a
+      - name: Install Nix
+        uses: https://github.com/DeterminateSystems/nix-installer-action@v4
+      - name: Run `nix build`
+        run: nix --version