diff --git a/.github/workflows/flake-update.yaml b/.github/workflows/flake-update.yaml
index 3d2d1c8..a9521c0 100644
--- a/.github/workflows/flake-update.yaml
+++ b/.github/workflows/flake-update.yaml
@@ -14,6 +14,8 @@ jobs:
       image: ghcr.io/catthehacker/ubuntu:runner-latest
     steps:
       - uses: actions/checkout@v3
+        with:
+          ref: master
       - uses: cachix/install-nix-action@v27
       - name: configure git
         run: |