diff --git a/.github/workflows/build-nix.yml b/.github/workflows/build-nix.yml
new file mode 100644
index 0000000..e60310d
--- /dev/null
+++ b/.github/workflows/build-nix.yml
@@ -0,0 +1,42 @@
+name: Build system configurations
+
+on:
+  pull_request:
+
+jobs:
+  build-x86_64-demeter:
+    runs-on: ubuntu-24.04
+    permissions:
+      contents: read
+      id-token: write
+    steps:
+      - name: Free Disk Space (Ubuntu)
+        uses: Jayllyz/free-disk-space@perf/use-rmz
+      - uses: actions/checkout@v4
+      - name: Check Nix flake Nixpkgs inputs
+        uses: DeterminateSystems/flake-checker-action@main
+      - uses: DeterminateSystems/nix-installer-action@main
+        with:
+          github-token: ${{ secrets.GH_TOKEN_FOR_UPDATES }}
+      - name: Build demeter
+        run: |
+          # nix flake check --all-systems
+          nix build .#nixosConfigurations.demeter.config.system.build.toplevel
+  build-aarch64-callisto:
+    runs-on: ubuntu-24.04-arm
+    permissions:
+      contents: read
+      id-token: write
+    steps:
+      - name: Free Disk Space (Ubuntu)
+        uses: Jayllyz/free-disk-space@perf/use-rmz
+      - uses: actions/checkout@v4
+      - name: Check Nix flake Nixpkgs inputs
+        uses: DeterminateSystems/flake-checker-action@main
+      - uses: DeterminateSystems/nix-installer-action@main
+        with:
+          github-token: ${{ secrets.GH_TOKEN_FOR_UPDATES }}
+      - name: Build callisto
+        run: |
+          # nix flake check --all-systems
+          nix build .#nixosConfigurations.callisto.config.system.build.toplevel