diff --git a/.github/workflows/check-ocaml.yml b/.github/workflows/check-ocaml.yml
index 18241b0..d3da8a1 100644
--- a/.github/workflows/check-ocaml.yml
+++ b/.github/workflows/check-ocaml.yml
@@ -20,6 +20,7 @@ jobs:
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
+            flake-registry =  https://raw.githubusercontent.com/akirak/flake-pins/master/registry.json
 
       - uses: cachix/cachix-action@v14
         with: