diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 19933626..90130412 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,6 +1,8 @@
 name: CI
 on:
   pull_request:
+    branches:
+      - master
 jobs:
   ci-matrix:
     runs-on: ubuntu-20.04
diff --git a/.github/workflows/website.yml b/.github/workflows/website.yml
index f0f13140..8e3f11ee 100644
--- a/.github/workflows/website.yml
+++ b/.github/workflows/website.yml
@@ -17,7 +17,7 @@ jobs:
           elm-version: 0.19.1
       - uses: cachix/install-nix-action@v16
         with:
-          nix_path: nixpkgs=channel:nixos-20.09
+          nix_path: nixpkgs=channel:nixos-21.11
       - name: Print nixpkgs version
         run: nix-instantiate --eval -E '(import <nixpkgs> {}).lib.version'
       - name: Build website (${{ env.DOCSPELL_VERSION }})