diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 61c2927..7b2fa30 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -44,9 +44,9 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: DeterminateSystems/nix-installer-action@main
+      - uses: DeterminateSystems/nix-installer-action@v17
 
-      - uses: DeterminateSystems/magic-nix-cache-action@main
+      - uses: DeterminateSystems/magic-nix-cache-action@v9
 
       - name: nix flake check
         run: nix flake check