diff --git a/.github/workflows/eval.yaml b/.github/workflows/eval.yaml
index 494704f..63c71ec 100644
--- a/.github/workflows/eval.yaml
+++ b/.github/workflows/eval.yaml
@@ -18,6 +18,10 @@ jobs:
 
       - name: Install Nix
         uses: cachix/install-nix-action@v25
+        with:
+          extra_nix_conf: |
+            extra-trusted-public-keys = cache.garnix.io:CTFPyKSLcx5RMJKfLo5EEPUObbA78b0YQ2DTCJXqr9g=
+            extra-substituters = https://cache.garnix.io
 
       - name: Configure Git
         run: |