diff --git a/.github/workflows/nix-action-coq-8.16-macos.yml b/.github/workflows/nix-action-coq-8.16-macos.yml
index 018222ffa..2b65d74a2 100644
--- a/.github/workflows/nix-action-coq-8.16-macos.yml
+++ b/.github/workflows/nix-action-coq-8.16-macos.yml
@@ -19,7 +19,7 @@ jobs:
         fetch-depth: 0
         ref: ${{ env.tested_commit }}
     - name: Cachix install
-      uses: cachix/install-nix-action@V27
+      uses: cachix/install-nix-action@V28
       with:
         nix_path: nixpkgs=channel:nixpkgs-unstable
     - name: Cachix setup metacoq
@@ -59,7 +59,7 @@ jobs:
         fetch-depth: 0
         ref: ${{ env.tested_commit }}
     - name: Cachix install
-      uses: cachix/install-nix-action@V27
+      uses: cachix/install-nix-action@V28
       with:
         nix_path: nixpkgs=channel:nixpkgs-unstable
     - name: Cachix setup metacoq
@@ -104,7 +104,7 @@ jobs:
         fetch-depth: 0
         ref: ${{ env.tested_commit }}
     - name: Cachix install
-      uses: cachix/install-nix-action@V27
+      uses: cachix/install-nix-action@V28
       with:
         nix_path: nixpkgs=channel:nixpkgs-unstable
     - name: Cachix setup metacoq
diff --git a/.github/workflows/nix-action-coq-8.16-ubuntu.yml b/.github/workflows/nix-action-coq-8.16-ubuntu.yml
index 0fb816b29..c362652f5 100644
--- a/.github/workflows/nix-action-coq-8.16-ubuntu.yml
+++ b/.github/workflows/nix-action-coq-8.16-ubuntu.yml
@@ -19,7 +19,7 @@ jobs:
         fetch-depth: 0
         ref: ${{ env.tested_commit }}
     - name: Cachix install
-      uses: cachix/install-nix-action@V27
+      uses: cachix/install-nix-action@V28
       with:
         nix_path: nixpkgs=channel:nixpkgs-unstable
     - name: Cachix setup metacoq
@@ -59,7 +59,7 @@ jobs:
         fetch-depth: 0
         ref: ${{ env.tested_commit }}
     - name: Cachix install
-      uses: cachix/install-nix-action@V27
+      uses: cachix/install-nix-action@V28
       with:
         nix_path: nixpkgs=channel:nixpkgs-unstable
     - name: Cachix setup metacoq
@@ -104,7 +104,7 @@ jobs:
         fetch-depth: 0
         ref: ${{ env.tested_commit }}
     - name: Cachix install
-      uses: cachix/install-nix-action@V27
+      uses: cachix/install-nix-action@V28
       with:
         nix_path: nixpkgs=channel:nixpkgs-unstable
     - name: Cachix setup metacoq