diff --git a/.github/workflows/build-with-nix.yml b/.github/workflows/build-with-nix.yml
index 962d40c1..3a4b1a4c 100644
--- a/.github/workflows/build-with-nix.yml
+++ b/.github/workflows/build-with-nix.yml
@@ -22,6 +22,7 @@ jobs:
       with:
         name: tket
         authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+        installCommand: "nix profile install --accept-flake-config nixpkgs#cachix"
     - name: Build pytket-cutensornet
       run: nix build --accept-flake-config
   test:
@@ -34,5 +35,6 @@ jobs:
       with:
         name: tket
         authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+        installCommand: "nix profile install --accept-flake-config nixpkgs#cachix"
     - name: Test pytket-cutensornet
       run: nix run .#tests --accept-flake-config