diff --git a/.github/workflows/build-cache.yml b/.github/workflows/build-cache.yml
index 9a5c1945..46f1ec61 100644
--- a/.github/workflows/build-cache.yml
+++ b/.github/workflows/build-cache.yml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: cachix/install-nix-action@latest
+      - uses: cachix/install-nix-action@30
       - uses: cachix/cachix-action@v15
         with:
           name: mrjones2014-dotfiles
diff --git a/.github/workflows/check-flake.yml b/.github/workflows/check-flake.yml
index 7b3569a8..d79bb563 100644
--- a/.github/workflows/check-flake.yml
+++ b/.github/workflows/check-flake.yml
@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: cachix/install-nix-action@latest
+      - uses: cachix/install-nix-action@30
       - uses: cachix/cachix-action@v15
         with:
           name: mrjones2014-dotfiles
diff --git a/.github/workflows/github-pages.yml b/.github/workflows/github-pages.yml
index 70dd0ff2..24951335 100644
--- a/.github/workflows/github-pages.yml
+++ b/.github/workflows/github-pages.yml
@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: cachix/install-nix-action@latest
+      - uses: cachix/install-nix-action@30
       - name: Build mdbook site
         run: nix build ./docs/
       - name: Deploy
diff --git a/.github/workflows/update-flake.yml b/.github/workflows/update-flake.yml
index 2c40ebb5..cc110d77 100644
--- a/.github/workflows/update-flake.yml
+++ b/.github/workflows/update-flake.yml
@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
-    - uses: cachix/install-nix-action@latest
+    - uses: cachix/install-nix-action@30
     - uses: cachix/cachix-action@v15
       with:
         name: mrjones2014-dotfiles