diff --git a/.github/workflows/docs-preview.yml b/.github/workflows/docs-preview.yml
index 97f9e4b..e9f274c 100644
--- a/.github/workflows/docs-preview.yml
+++ b/.github/workflows/docs-preview.yml
@@ -49,6 +49,12 @@ jobs:
     if: ${{ !cancelled() && github.event.pull_request.head.repo.full_name == github.repository && (github.event.action == 'closed' || needs.build.result == 'success') }}
     runs-on: ubuntu-latest
 
+    # Pages builds share gh-pages, so wait for each deployment before the next push.
+    concurrency:
+      group: rustdoc-preview-deploy
+      cancel-in-progress: false
+      queue: max
+
     permissions:
       actions: read
       contents: write
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 2184b65..05019f6 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -86,7 +86,7 @@ jobs:
           persist-credentials: false
 
       - name: Check GitHub Actions security
-        uses: zizmorcore/zizmor-action@3dc1ecc9bcb9e94e9b2c709687979e1298497054 # v0.6.2
+        uses: zizmorcore/zizmor-action@cc914d7f3750a2d13d75c7f184a1060aa0e9d482 # v0.6.4
         with:
           advanced-security: false
           annotations: true