diff --git a/.github/workflows/update-flake-lock.yml b/.github/workflows/update-flake-lock.yml
index b62811b..407bbc2 100644
--- a/.github/workflows/update-flake-lock.yml
+++ b/.github/workflows/update-flake-lock.yml
@@ -14,7 +14,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Install Nix
-        uses: DeterminateSystems/nix-installer-action@main
+        uses: DeterminateSystems/nix-installer-action@v9
 
       - name: Install Mention deploy key
         uses: webfactory/ssh-agent@v0.8.0