diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 60aed67cea03..3b289413e6fb 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -65,6 +65,7 @@ jobs:
           name: ${{ vars.CACHIX_NAME || 'nixpkgs-ci' }}
           extraPullNames: nixpkgs-ci
           authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
+          pushFilter: -source$
 
       - run: nix-env --install -f pinned -A nix-build-uncached
 
diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index d58358e23aa7..3dbbb9d2dff7 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -116,6 +116,7 @@ jobs:
           name: ${{ vars.CACHIX_NAME || 'nixpkgs-ci' }}
           extraPullNames: nixpkgs-ci
           authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
+          pushFilter: -source$
 
       - name: Build codeowners validator
         run: nix-build trusted/ci --arg nixpkgs ./pinned -A codeownersValidator