diff --git a/.github/workflows/update-ghc.yaml b/.github/workflows/update-ghc.yaml
index b17d81820..dc48ba6fe 100644
--- a/.github/workflows/update-ghc.yaml
+++ b/.github/workflows/update-ghc.yaml
@@ -22,7 +22,7 @@ jobs:
       - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
         with:
           ref: master
-      - uses: cachix/install-nix-action@456688f15bc354bef6d396e4a35f4f89d40bf2b7 # v31.8.2
+      - uses: cachix/install-nix-action@0b0e072294b088b73964f1d72dfdac0951439dbd # v31.8.4
         with:
           nix_path: nixpkgs=nixpkgs/default.nix
       - name: Fetch updates
diff --git a/.github/workflows/workflow.yaml b/.github/workflows/workflow.yaml
index c47ef92f4..9c9ba0f25 100644
--- a/.github/workflows/workflow.yaml
+++ b/.github/workflows/workflow.yaml
@@ -71,7 +71,7 @@ jobs:
         with:
           path: ~/repo-cache
           key: repo-cache-${{ runner.os }}-nixpkgs-${{ env.cache-version }}
-      - uses: cachix/install-nix-action@456688f15bc354bef6d396e4a35f4f89d40bf2b7 # v31.8.2
+      - uses: cachix/install-nix-action@0b0e072294b088b73964f1d72dfdac0951439dbd # v31.8.4
         with:
           nix_path: nixpkgs=./nixpkgs/default.nix
           extra_nix_config: |