diff --git a/.github/workflows/main.yaml b/.github/workflows/main.yaml
index 52b5114..039d309 100644
--- a/.github/workflows/main.yaml
+++ b/.github/workflows/main.yaml
@@ -13,6 +13,14 @@ jobs:
 
     - name: Install Nix
       uses: cachix/install-nix-action@v27
+      with:
+        install_url: https://releases.nixos.org/nix/nix-2.18.1/install
+
+    - name: Nix config
+      run: |
+        echo "============================"
+        cat /etc/nix/nix.conf
+        echo "============================"
 
     - name: Run tests
       run: nix shell -c ./run-tests.py