diff --git a/.github/workflows/haskell.yml b/.github/workflows/haskell.yml
index d16fcd241..db39436d6 100644
--- a/.github/workflows/haskell.yml
+++ b/.github/workflows/haskell.yml
@@ -148,16 +148,27 @@ jobs:
     #  uses: mxschmitt/action-tmate@v3
     #  with:
     #     limit-access-to-actor: true
+    - name: Install Nix with good defaults
+      if: runner.os == 'Linux' && (matrix.ghc == '8.10.7' || matrix.ghc == '9.6.2')
+      uses: cachix/install-nix-action@v26
+      with:
+        extra_nix_config: |
+          trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= loony-tools:pr9m4BkM/5/eSTZlkQyRt57Jz7OMBxNSUiMC4FkcNfk=
+          substituters = https://cache.iog.io/ https://cache.zw3rk.com/ https://cache.nixos.org/
+        nix_path: nixpkgs=channel:nixos-unstable"
+        github_access_token: ${{ secrets.GITHUB_TOKEN }}
 
     - name: Force Cabal and HLS to populate their caches
       if: runner.os == 'Linux' && (matrix.ghc == '8.10.7' || matrix.ghc == '9.6.2')
       run: |
-        timeout 15m bash -c "nix develop github:input-output-hk/devx#${{ matrix.ghc == '8.10.7' && 'ghc810' || matrix.ghc == '9.6.2' && 'ghc96' }} --command bash -c 'cabal update; haskell-language-server --project-ghc-version'"
+        timeout 15m bash -c \
+          "nix develop github:input-output-hk/devx#${{ matrix.ghc == '8.10.7' && 'ghc810' || matrix.ghc == '9.6.2' && 'ghc96' }} --command \
+            bash -c 'cabal update; haskell-language-server --project-ghc-version'"
       shell: bash
 
     - name: Cache build artifacts (used to speed up GitHub Codespaces bootstrapping)
       if: runner.os == 'Linux' && (matrix.ghc == '8.10.7' || matrix.ghc == '9.6.2')
-      uses: actions/upload-artifact@v2
+      uses: actions/upload-artifact@v4
       with:
         name: cache-${{ github.sha }}-${{ matrix.ghc == '8.10.7' && 'ghc810' || matrix.ghc == '9.6.2' && 'ghc96' }}
         path: |